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STAR Protocols

Elsevier BV

Preprints posted in the last 30 days, ranked by how well they match STAR Protocols's content profile, based on 18 papers previously published here. The average preprint has a 0.02% match score for this journal, so anything above that is already an above-average fit.

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A standardized method for T cell receptor (TCR) replacement through CRISPR-Cas9 mediated editing and retroviral transduction of primary murine naïve CD8 T cells

Tong, N. M.; Attanasio, J.; Fagerberg, E.; Connolly, K. A.; Joshi, N. S.

2026-08-19 immunology 10.64898/2026.08.17.745264 medRxiv
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CD8 T cells play a central role in immune responses to infection and cancer. However, the diversity of T cell receptor (TCR) specificities makes it challenging to study the mechanisms that regulate T cell activation, differentiation, and effector function. Beyond TCR transgenic mouse models, various complex genome-editing approaches have been employed to overcome this challenge. However, these strategies are often technically demanding, time-intensive, and difficult to adapt. Investigators who are interested in testing de novo TCRs under their chosen experimental conditions would benefit from a standardized and accessible method. Here, we describe a protocol that combines ribonucleoprotein (RNP)-based CRISPR-Cas9 editing with retroviral transduction to enable efficient genetic manipulation of murine CD8 T cells. We show that T cells engineered via this protocol can be generated at sufficient scale for downstream in vitro assays and in vivo adoptive transfer experiments. We expect this method will be useful for investigators who require a standardized and accessible way to study how TCR specificity impacts CD8 T cell responses.

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A robust approach for preserving and sectioning fragile 3D spheroids for high-quality histological analysis

Cervantes-Rivera, R.; Figueroa Ortiz, S. J.; Romero Rosas, A. Z.; Sanchez Orozco, A.; Herrera-Vargas, M. A.; Melendez-Herrera, E.; Lopez-Rodriguez, M.; Ochoa-Zarzosa, A.; Lopez-Meza, J. E.

2026-08-11 cell biology 10.64898/2026.08.05.743094 medRxiv
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Three-dimensional (3D) spheroid models have become essential in cancer biology, drug screening, and tissue engineering. However, their small size, fragile structure, and tendency to disintegrate during routine histoprocessing present persistent technical challenges. Conventional paraffin embedding often results in tissue fragmentation, loss of spatial orientation, and poor section quality, whereas cryosectioning often compromises cellular morphology. Here, we present a robust, cost-effective protocol for preserving and sectioning fragile 3D spheroids, resulting in high-quality histological sections with intact architecture and excellent cellular detail. The method involves optimized handling and embedding procedures that stabilize spheroids during standard formalin fixation, paraffin infiltration, and microtomy, eliminating mechanical distortion and preserving spherical integrity for consistent sectioning. We demonstrate successful application across different cell line spheroids, with subsequent compatibility with hematoxylin and eosin (H&E) staining protocols. Compared to conventional methods, our approach significantly reduces sample loss, improves inter-section reproducibility, and preserves fine structural features such as necrotic cores, proliferative zones, and extracellular matrix components. This protocol provides a reliable, accessible solution for routine histological analysis of fragile 3D spheroids, facilitating more accurate morphological and molecular assessment in translational research settings. Key featuresO_LIMaintains spheroid integrity: Prevents mechanical distortion, fragmentation, and loss of spatial orientation during processing. C_LIO_LISignificantly reduces sample loss: Decreases failure rate compared to traditional methods, conserving valuable samples. C_LIO_LIBroad spheroid compatibility: Works effectively with primary tumor-derived, stem cell-derived, and co-culture spheroid models. C_LIO_LIEnables high-quality sectioning and staining: Delivers consistent, reproducible sections that are fully compatible with H&E, IHC, and IF. C_LI Graphical overview O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=140 SRC="FIGDIR/small/743094v1_ufig1.gif" ALT="Figure 1"> View larger version (44K): org.highwire.dtl.DTLVardef@1670c4org.highwire.dtl.DTLVardef@145810aorg.highwire.dtl.DTLVardef@1accb1org.highwire.dtl.DTLVardef@17481c0_HPS_FORMAT_FIGEXP M_FIG C_FIG

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Interval-zone free-flow electrophoresis as a charge-specific dimension for native isolation of thylakoid membrane protein complexes

Eichacker, L. A.; Weber, G.

2026-08-28 plant biology 10.64898/2026.08.27.747539 medRxiv
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Native polyacrylamide gel electrophoresis is the standard first analytical step after detergent solubilization of thylakoid membranes. It separates photosystem supercomplexes by size and shape, but it forces a polydisperse mixture of protein-detergent particles through a gel of limited pore diameter. Interval-zone free-flow electrophoresis (iZE-FFE) performs that first electrophoretic step in free solution, without ampholytes or immobilines, and returns the complexes as a liquid fraction series ordered by net charge. We describe the operational cycle of iZE, show that bromophenol blue reports the charge density of {beta}-dodecylmaltoside micelles, and apply iZE to Arabidopsis thaliana thylakoid extracts from two sequential solubilization campaigns. After a two-step digitonin then digitonin/{beta}-dodecylmaltoside extraction (experiment 6874), SDS-PAGE of the iZE fractions is crowded: high-molecular mass protein-lipid assemblies of photosystem I and photosystem II release the same subunits into many wells. Native-PAGE of the same fractions resolves ATP-synthase from PSI, a free LHCII pool, anodic PSII, and cathodic PSI, including PSI with and without LHCII. A three-step extraction with a single pH working window (experiment 7154) confirms this charge order. Lowering residual detergent in consecutive extracts still produces partly solubilized high-mass assemblies, whereas a final {beta}-dodecylmaltoside step releases the C2S2M2/C2S2M/C2S2 PSII series and a single PSI band. iZE is therefore a charge-first, orthogonal dimension for native thylakoid biochemistry. Native-PAGE, not SDS-PAGE, is the proper second dimension while solubilization remains incomplete.

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Click-Prep: An Interactive Data Preparation Tool for Click-qPCR

Kubota, A.; Tajima, A.

2026-08-24 bioinformatics 10.64898/2026.08.20.745930 medRxiv
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Click-qPCR is a browser-based application for relative qPCR analysis that requires a tidy-format CSV file containing four columns: sample, group, gene, and Cq. Preparing this input from qPCR instrument output typically requires manual reformatting and calculation of mean Cq values for technical replicates. To simplify this process, we developed Click-Prep (https://kubo-azu.shinyapps.io/Click-Prep/), an interactive web-based application designed specifically to create Click-qPCR input files. Click-Prep imports CSV, TXT, TSV, and XLS/XLSX files and supports skipping of instrument-generated metadata rows, interactive column mapping, and manual assignment of experimental groups. Users can review technical-replicate measurements, exclude selected rows according to predefined quality-control criteria, and calculate mean Cq values for each sample-group-target combination. Missing or nonnumeric Cq values are flagged for review and must be resolved before the mean is calculated. Click-Prep can also combine compatible formatted CSV files, such as datasets obtained from separate qPCR plates. The resulting dataset is exported as a standardized CSV file containing the four fields required by Click-qPCR. By integrating these operations into a guided browser-based workflow, Click-Prep enables users to prepare Click-qPCR input files rapidly and consistently without programming.

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Knockout and re-expression system for mutant analysis in primary mouse T cells

Morfos, V.; Frie, M. C.; Peschkov, D.; Wagner, J.; Lillemeier, B. F.; Brzostek, J.

2026-08-28 immunology 10.64898/2026.08.25.746944 medRxiv
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We describe here an efficient method for gene editing in mouse T cells, based on well-established, high-efficiency retroviral transduction protocols. Our platform allows analysis of mutant phenotypes in primary murine T cells in vitro and in vivo. This approach uses a single retroviral vector to simultaneously knockout an endogenous gene and ectopically express its mutant version. This knockout/re-expression vector can be used as the only plasmid to transduce Cas9-expressing T cells, or used together with a Cas9 retroviral vector to transduce T cells from any mouse strain. We validated the system for analysis of murine T cells by targeting key molecules in proximal T cell signaling, i.e. CD3{gamma} and Zap70. We obtain high knockout and re-expression efficiencies in both Cas9-expressing and non-Cas9 T cells. Knockout efficiencies can be further improved by gRNA multiplexing. Endogenous proteins compete with their ectopically expressed mutants or tagged versions for cellular location, protein interactions and cellular functions. Here, we quantified the incorporation of CD3{gamma}-GFP into surface T cell receptor (TCR) complexes. Our data shows that the knockout and re-expression platform improves integration of CD3{gamma}-GFP into the TCR. Therefore, eliminating competition between endogenous and ectopic proteins benefits analyses of protein assemblies and signaling pathways in primary T cells. Furthermore, we validated advantages of our system for mutant analysis using wild-type and mutant Zap70s. Zap70 mutants deficient in TCR binding or kinase activity show their phenotypes only in the absence of endogenous protein, further validating our knockout/re-expression approach. Most importantly, this system can be used to generate gene-edited primary T cells for in vivo studies, such as the quantification of anti-tumor responses. Our knockout and re-expression platform provides a useful gene editing tool for primary T cells in fundamental research and immunotherapy development.

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A Robust and Scalable Workflow for the Production of Circular Single-Stranded DNA for Genome Engineering Applications

Mathews, S.; Kapoor, M.; Sivacoumar, A.; Acharya, R.; Maiti, S.; Chakraborty, D.

2026-08-17 molecular biology 10.64898/2026.08.14.743880 medRxiv
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Circular single-stranded DNA (cssDNA) is a versatile biomolecule with applications spanning genome editing, DNA nanotechnology, synthetic biology, molecular diagnostics, and aptamer development. Compared with linear single-stranded DNA, cssDNA offers enhanced structural stability, resistance to in-cellulo degradation by exonucleases and enables the generation of long, sequence-defined DNA molecules that are difficult to obtain through conventional chemical synthesis methods. Despite its growing utility, widespread adoption of cssDNA has been limited by the lack of accessible, scalable, and cost-effective production methods, with many existing workflows relying on specialised reagents, extensive optimisation, or commercially synthesised DNA. Here, we present a streamlined, end-to-end protocol for the laboratory-scale production of high-purity cssDNA using an M13 phagemid-based system and standard molecular biology laboratory infrastructure. The workflow encompasses bacterial culture, phage amplification, nuclease treatment, phage precipitation, anion-exchange purification, and quality control, with practical optimisations to improve yield, reproducibility, and scalability. Using this approach, yields range from 120-195 {micro}g of purified cssDNA from 300 mL of culture supernatant. The protocol provides detailed guidance on critical process parameters, troubleshooting, and quality assessment, enabling reliable production of cssDNA suitable for a wide range of downstream molecular biology and genome engineering applications.

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DrosoTracker: a web application with a self-calibrating thermal model for husbandry scheduling and lifespan analysis in Drosophila melanogaster

Asti Tello, G. S.; Melani, M.; Liberman, A. C.

2026-08-11 developmental biology 10.64898/2026.08.10.743933 medRxiv
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Planning husbandry tasks and experiments with Drosophila melanogaster requires converting a target date into development times that depend on the rearing temperature. This calculation needs to be done for each cross, genotype, and temperature, and the risk of error grows quickly. Available laboratory management tools let users register stocks, crosses, and track them, but they do not create schedules based on a clear, adjustable thermal model. To fill that gap, we developed DrosoTracker, a self-contained web application that works offline and predicts Drosophila development with a thermal summation model recalibrated through regression on data from Powsner (1935) (T0 = 11.78 {degrees}C, DD = 116.38 {degrees}C{middle dot}days, R{superscript 2} = 0.997). The model offers an optional two-level calibration driven by user observations. A wild-type strain first adjusts the model to the laboratorys own conditions. Then each genotype is calibrated against that reference using a random-effects shrinkage estimator that accounts for measurement error and between-batch variability. The model creates schedules for husbandry tasks, evaluates adult cohort survival with the Kaplan-Meier estimator and the log-rank test, and calculates sample size for lifespan studies using Schoenfelds formula. The quantitative components were checked against independent references, including Rs survival package and manual calculations. Ongoing work is focused on validating the calibrated model using cohorts specifically bred for this purpose. DrosoTracker runs entirely in the browser, stores data locally, and is available in English and Spanish.

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TxNova: recovery of recurrent unannotated intergenic splice loci from existing bulk RNA-seq alignments

Li, Z.; James, A.; Li, S.

2026-08-25 bioinformatics 10.64898/2026.08.24.746847 medRxiv
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Background. Reference catalogs such as GENCODE capture most stably expressed mammalian genes but may not include condition-restricted or low-abundance transcripts. Reads supporting unannotated intergenic splice junctions are generally absent from annotation-restricted gene-count matrices; transcript assemblers may reconstruct a subset as novel models, but those models are typically handled separately from the annotated gene-count universe. TxNova is a lightweight command-line tool that directly indexes these unannotated splices from existing BAM files - without an external assembler, gffcompare, or workflow manager - yielding candidate leads for bench validation rather than standalone discovery claims. Methods. TxNova retains CIGAR N junctions from STAR/HISAT2 BAM files that recur in >= 2 samples and are absent from a comprehensive annotation, clusters them into residual loci, and counts each locus alongside annotated genes in a unified matrix. Structure gates - canonical splice motif, same-strand distance, coverage valley, bridging-junction absence, minimum length - remove likely artifacts to yield structure-pass models. An optional contrast filter retains loci detected in treatment but nearly silent in control. Results. A residual splice is a recurrent, unannotated CIGAR N junction that does not overlap any annotated gene body; intronic and antisense channels are out of scope. Across four published mouse treatment arms (GSE221720, GSE166522, GSE157460, GSE193335), harvest catalogs yielded 464, 657, 789, and 594 loci. On GSE221720, 45% of loci (209/464) shared an exact intron with another series, versus 0.074% for excluded junctions; a coordinate-placement control yielded 0/5,000 matches for length-matched intergenic decoys. Masked-gene recovery reached 87.6% (176/201) overall and 99.4% (176/177) among genes with a leak junction - sensitivity rather than precision estimates. An optional contrast provides a presence/absence screen on interval TPM. Residual models are partial reconstructions requiring cloning, RACE, or targeted proteomics for confirmation. Conclusions. TxNova produces a reproducible intergenic residual-locus catalog from existing BAM files, with four downloadable mouse injury/infection catalogs. Cross-series recurrence and coordinate-based null controls support reproducibility above simple placement backgrounds but do not by themselves establish biological validity. The optional contrast step offers a practical screen for candidate leads warranting experimental validation.

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Cesium-137 and X-Ray Irradiation Yield Comparable Immune Phenotypes and Activation States in Bone Marrow Chimeric Studies

Bastian, A. G.; Livingston, E. W.; Zimmerman, M. P.; Reynolds, A. G.; Chong, W. L.; Cox, E. K.; Wang, H.; Yuan, H.; Miller, B. C.

2026-08-28 immunology 10.64898/2026.08.25.746967 medRxiv
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Bone marrow chimeras are widely used to study immune development and function. As the field moves from cesium-137 (137Cs)-based irradiators to X-ray irradiators for safety reasons, it is essential to determine if there are differences in immune system reconstitution after irradiating mice with one of these two radiation sources. Here, we performed a comprehensive immunological comparison of mice lethally irradiated with 137Cs or one of two different X-ray platforms and reconstituted with congenic bone marrow. Mice received 12 Gy total body radiation in two 6 Gy sessions followed by intravenous transfer of donor hematopoietic stem cells and were analyzed eight weeks post-transplant. We assessed mouse survival, donor chimerism, immune cell subset distribution, and activation states across multiple organs (bone marrow, spleen, lymph nodes, liver, and lung). All groups exhibited comparable survival and high levels of donor chimerism, with expected organ-specific reconstitution patterns. Immune lineage distributions, CD4/CD8 ratios, and activation states did not differ by irradiation type. Host-derived radioresistant cells were also similar across all irradiation groups and were predominantly composed of T cells skewed toward an activated phenotype. Overall, our data show that X-ray irradiation with proper filters and energy levels (225 KVp and 320 KVp) can yield equivalent immunological outcomes, including immune reconstitution and activation states, as compared to the same radiation dose from 137Cs-based irradiation in bone marrow chimera models. These results support the continued adoption of X-ray irradiation systems in place of 137Cs for generating bone marrow chimeras to be used across a wide range of immunologic studies.

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Sequential VEGF-A165 plasmid and AAV-follistatin gene therapy enhances muscle hypertrophy and capillarisation in C57BL/6 mice

Vakhrusheva, A.; Nedorubov, A.; Leshko, V.; Morgunov, I.

2026-08-28 physiology 10.64898/2026.08.26.747237 medRxiv
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Introduction. Skeletal muscle loss in sarcopenia and neuromuscular disorders remains a major unmet medical need. AAV9-delivered follistatin (FST), a myostatin/activin antagonist, induces muscle hypertrophy; however, fibre growth without adequate vascular adaptation may limit therapeutic efficacy. We evaluated whether co-administration of a VEGF-A165 plasmid enhances the hypertrophic and angiogenic effects of intramuscular AAV-FST gene transfer in C57BL/6 mice. Methods. Thirty-six C57BL/6 mice (18 males, 18 females) were assigned to PBS vehicle (n=10), AAV-FST (1 x 10^11 vg; n=10), VEGF plasmid (100 ug; n=6), or combination treatment (VEGF plus AAV-FST; n=10). The contralateral hindlimb served as an internal control. Endpoints at Day 115 included hindlimb muscle mass ratio (R/L), transgene expression, FST protein levels, muscle fibre morphometry, capillary density, and safety assessments. Results. Combination therapy produced the highest R/L ratio (1.176 +/- 0.091; p=0.004; d=2.04), whereas AAV-FST alone showed a borderline effect (R/L=1.113; p=0.050). Compared with AAV-FST monotherapy, combination treatment increased muscle FST mRNA approximately 2.1-fold, protein levels approximately 2.0-fold, and the muscle-to-liver expression ratio 2.6-fold. It also induced larger muscle fibres and doubled CD31+ vessel counts versus AAV-FST alone, indicating simultaneous hypertrophy and angiogenesis. No adverse haematological, biochemical, or histopathological findings were observed. Discussion. Combined AAV-FST and VEGF therapy enhanced local muscle hypertrophy, increased capillary density, and improved the muscle-to-liver transgene expression profile compared with AAV-FST monotherapy. The regimen was well tolerated and supports further evaluation of angiogenic preconditioning as a strategy to improve muscle-directed gene therapy for muscle-wasting disorders.

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An open multimodal spatial resource integrating same-tissue transcriptomics, proteomics, and histology

Duchini, E.; Tsao, C.; Madore, J.; Ashhurst, T. M.; De Almeida Silva, J.; Shin, J.-S.; Gupta, R.; McCaughan, G.; Palendira, U.; Liu, K.; Ferguson, A.; Marsh-Wakefield, F.

2026-08-21 immunology 10.64898/2026.08.17.742355 medRxiv
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Spatial transcriptomic and proteomic technologies provide complementary insights into tissue organisation, cellular phenotype and function, yet integrating these modalities on the same tissue section remains technically challenging. Sequential workflows must preserve RNA integrity, antigenicity and tissue morphology while maintaining accurate spatial registration. At present, publicly available multimodal datasets suitable for computational method development remain limited. Here, we present a workflow for sequential 10x Genomics Xenium spatial transcriptomics, COMET cyclic immunofluorescence, and haematoxylin and eosin (H&E) histological staining on the same formalin-fixed paraffin-embedded tissue section. We demonstrate this approach across multiple biologically distinct human tissues, including tonsil, hepatocellular adenoma, and matched tumour and non-tumour hepatocellular carcinoma, illustrating the widespread applicability of the workflow beyond a single tissue type. Following image registration, Xenium-derived cell segmentations were applied to protein images to generate integrated single-cell transcriptomic and proteomic measurements for downstream analyses. To facilitate community reuse, we publicly release four representative aligned tissue cores together with transcript coordinates, multiplex protein images, H&E images, cell segmentations, and integrated single-cell datasets. We additionally introduce UnumLocalia, an open-source visualisation and data extraction tool that enables interactive exploration of aligned multimodal images, supports user-defined cell segmentation, and allows export of integrated single-cell data for downstream analyses. Together, this technical protocol, workflow, software, and openly available dataset provide a reusable resource for multimodal spatial biology, supporting advances in biological discovery, computational method development, multimodal data integration, and validation of emerging analytical approaches across complementary spatial technologies.

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A primary human muscle cell-based assay for detecting myasthenia gravis autoantibody binding and assessing AChR cluster impairment

Wolfsgruber, M.; Zimmermann, A.-S.; Starnberger, K.; Duckova, T.; Keritam, O.; Woehrleitner, A.; Weng, R.; Doksani, P.; Rocha, M.; Matus, N.; Tripkovic, K.; Pervez, M.; Fernandes-Rosenegger, P.; Faber, F.; Elmas, C.; Fichtner, M.; Maestri Tassoni, M.; Cetin, H.; Hoeftberger, R.; Zimprich, F.; Herbst, R.; Albrecht, C.; Hoffmann, S.; Weigl, L.; Winter, L.; Koneczny, I.

2026-08-13 neuroscience 10.64898/2026.08.10.743478 medRxiv
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Myasthenia gravis (MG) is an autoimmune disease caused by pathogenic autoantibodies against proteins at the neuromuscular junction (NMJ). The diagnosis and clinical management of MG patients largely relies on the detection of antigen-specific autoantibodies targeting acetylcholine receptor (AChR) or muscle-specific kinase (MuSK). Yet a subset of patients remains seronegative for known MG autoantibodies, highlighting a critical need for alternative approaches to identify pathogenic NMJ antibodies. We established a new human in vitro model of the NMJ based on primary human muscle cells that recapitulates key features of the NMJ: differentiation to myotubes, expression of key NMJ proteins and formation of postsynaptic AChR clusters in response to agrin stimulation. The model allows new insights into myogenesis and genetic muscle diseases, and the new muscle cell-based assay (CBA) detected autoantibodies in sera from patients with AChR- and MuSK-positive MG with 96.43% sensitivity and 100% specificity, while healthy control sera showed no reactivity. Incubation with patient sera significantly reduced AChR clustering compared to controls, demonstrating functional pathogenic effects. Thus, we established a physiologically relevant human NMJ model that enables detection and functional characterization of neuromuscular autoantibodies. This novel approach addresses a key limitation of current antigen-specific diagnostics and provides a method for improved detection and characterization of MG antibodies, independent of antigen specificity. One Sentence SummaryWe established a postsynaptic human in vitro neuromuscular junction model to assess binding and pathogenicity of MG autoantibodies. Key messagesO_ST_ABSWhat is already known on this topic?C_ST_ABSCurrent diagnosis of myasthenia gravis (MG) relies largely on the detection of antigen-specific autoantibodies against AChR and MuSK, leaving a clinically relevant subset of patients seronegative. What are the new findings?We established a physiologically relevant human in vitro neuromuscular junction model based on primary human muscle cells and developed a novel muscle cell-based assay (CBA) for the detection of neuromuscular autoantibodies. How might this impact on clinical practice or future developments?The CBA detected autoantibodies in patients with AChR- or MuSK-positive MG with high sensitivity and specificity and demonstrated their functional pathogenic effects on AChR clustering. This antigen-independent approach may improve the detection and functional characterization of MG autoantibodies, particularly in patients who are seronegative in current diagnostic assays. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=130 SRC="FIGDIR/small/743478v1_ufig1.gif" ALT="Figure 1000"> View larger version (38K): org.highwire.dtl.DTLVardef@18ed154org.highwire.dtl.DTLVardef@151036corg.highwire.dtl.DTLVardef@1b7ab34org.highwire.dtl.DTLVardef@1490fe9_HPS_FORMAT_FIGEXP M_FIG C_FIG

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High-coverage DNA sequence and modification profiling of targeted genomic elements using Nanopore-based Cas12a Targeted Ligation and Enrichment Sequencing (nCasTLES).

Vantine, M.; Kishimoto, K.; Pacheco, B. A.; Flavahan, W. A.

2026-08-26 molecular biology 10.64898/2026.08.25.747114 medRxiv
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Third-generation sequencing technologies, such as nanopore sequencing, enable long-read sequencing and direct characterization of nucleic acid modifications at low cost. However, nanopore sequencing is limited by low throughput, necessitating targeted sequencing for interrogation of specific genomic elements. The current standard is nanopore Cas9-targeted sequencing (nCATS), which utilizes blunt-end cleavage of dephosphorylated DNA to render targeted DNA sites as the only ligation-capable ends for sequencing adapter addition. nCATS significantly improves on-target sequencing yield but suffers from lower total sequencing output and faster flow cell degradation, resulting in an increased cost per sequencing due to inert DNA. Here, we present a modified approach, based on creating predictable base overhangs with Cas12a/Cpf1 as ligation substrates for biotinylated oligos followed by bead enrichment, termed nanopore Cas-12a Targeted Ligation-Enrichment Sequencing, or nCasTLES. nCasTLES removes off-target DNA via bead washes rather than rendering it inert. Removal of the inert off-target DNA allows nCasTLES libraries to be pooled with other sequencing libraries in a single sequencing run to achieve equivalent on-target DNA sequencing as nCATs while improving overall yield of useful data and decreasing the speed of flow cell degradation. We demonstrate the power of nCasTLES to characterize methylation dynamics at a frequently-methylated gene promoter. We also directed the Cas12a cleavage to an integrated lentiviral vector, allowing us to assess clonality of a transfected population and interrogate the integration state and transgene effects in selected clones. Finally, we demonstrate the utility of nCasTLES increased flow cell throughput by spike-in of nCasTLES libraries to WGS libraries to also characterize genetic and modified base information, such as clonal copy number variation analysis or BrdU incorporation, alongside the targeted sequencing. This approach will enable highly focused genomic interrogation in combination with full throughput of off-target reads.

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FluoroFate: A generalisable platform for time-resolved single-cell analysis of cell fate enables quantification of cell death dynamics

Preedy, M. K.; Taylor-Hearn, I.; Ying, C.; Ford, M. J.; Jackson, I. J.; Gilmore, A.; Tergoankar, V.; Mort, R. L.

2026-08-20 cell biology 10.64898/2026.08.17.745187 medRxiv
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Fundamental cellular decisions of life and death are governed by intricate and tightly regulated intracellular signalling pathways that determine whether cells proliferate, enter quiescence, or undergo programmed cell death (apoptosis). Live-cell fluorescence imaging enables these processes to be observed in real time at single-cell resolution, but two problems limit their study. First, existing biosensors do not allow apoptotic status and cell cycle progression to be resolved in tandem within the same cell. Second, interpreting live-cell imaging data is challenging even where multiplex reporters exist, as the biological meaning of fluorescent signals depends on their temporal ordering, and large-scale imaging experiments generate complex, multidimensional data that are difficult to analyse systematically and at scale. Here we address both problems. We present FluoroFate, a generalisable and user-friendly graphical interface-driven tool for time-resolved single-cell analysis of multiplex live-cell imaging datasets, which integrates existing, robust deep learning-based segmentation, cell tracking, and temporal classification methods to quantify fluorescent reporter dynamics in individual cells across time without the need for specialist computational expertise. Alongside FluoroFate, we develop tricistronic Fluorescent Ubiquitination-based Cell Cycle Indicator (Fucci) and apoptosis biosensors, enabling simultaneous monitoring of cell cycle progression and caspase activation within the same cell. Applying FluoroFate, we resolve apoptotic and non-apoptotic cell death at the single-cell level based on the temporal ordering of Annexin V and propidium iodide signals, identifying distinct kinetic and phenotypic cell death profiles in response to pharmacological perturbation. We highlight divergent temporal dynamics and modes of cell death between birinapant and cycloheximide treatment, reflecting differences in how TNF/TNFR1 signalling is disrupted by these agents. At the single-cell level, we uncover parallel, independently regulated death programmes, demonstrating that loss of RIPK1 selectively impairs apoptotic cell death whilst leaving non-apoptotic death largely unaffected. We then use FluoroFate to analyse timelapse images of our combined Fucci-apoptosis reporters, resolving cell cycle progression and caspase activation within the same cell over time. Together, FluoroFate and our new cell cycle and apoptosis biosensors represent a broadly applicable platform for extracting mechanistic insight from live-cell imaging data.

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ABISS: An Open-Source, Low-Cost Platform for Auditory and Visual Intrinsic Optical Signal Imaging

Qu, Z.; Kazemi, K.; Wu, T.; Doddapujar, S. N.; Marrazzo, T. A.; Gazzola, M.; Gritton, H.

2026-08-09 neuroscience 10.64898/2026.08.03.741387 medRxiv
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Defining the boundaries of functional cortical areas is increasingly important for targeted electro-physiology, optical imaging, viral delivery, and circuit manipulation. Intrinsic optical signal imaging (IOSI) provides a rapid and minimally invasive approach for mapping stimulus-evoked cortical activity, but its implementation often requires laboratory-specific combinations of stimulus-generation hardware, experiment-control software, synchronization devices, and data-acquisition systems. These requirements limit accessibility and hinder the use of IOSI as a routine functional mapping tool. Here, we present the Arduino-Based Intrinsic Stimulation System (ABISS), an open-source platform that integrates auditory and visual stimulus generation, trial timing, and image-acquisition triggering into a single programmable device. ABISS generates auditory tone stimuli, VGA-based visual stimuli, and tightly synchronized camera-trigger pulses without requiring a dedicated experiment-control system. Stimulus protocols are also fully modifiable in firmware. Performance was evaluated in auditory and visual cortices of mice. Engineering validation demonstrated accurate stimulus generation and synchronization between stimulus delivery and camera triggering over extended recording sessions. Biological validation showed that ABISS output results in auditory and visual intrinsic signal maps comparable to those obtained using highly specialized or commercial platforms. Together, these findings demonstrate the utility of a low-cost open-source platform for experimental control of intrinsic optical signal imaging. By reducing the technical and financial barriers associated with routine intrinsic optical imaging, ABISS facilitates broader adoption of functional cortical mapping as a tool for improved cortical localization in neuroscience experiments. Significance StatementFunctional cortical mapping is an increasingly important element of neuroscience experimental design as anatomical coordinates alone are often insufficient for defining cortical boundaries in individual animals. Intrinsic optical signal imaging provides an effective solution but traditionally requires specialized hardware, commercial stimulus-generation systems, and laboratory-specific synchronization workflows. We developed ABISS, an inexpensive, open-source platform that integrates auditory and visual stimulus generation with synchronized camera triggering in a single programmable device. ABISS produces functional cortical maps comparable to those obtainable with commercial or specialized systems while substantially reducing hardware complexity and cost. By making intrinsic optical signal imaging more accessible, ABISS lowers the practical barriers for routine functional mapping of the brain and promotes adoption of this important neuroscience technique.

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GlycoMeSH: linking glycan structures to biomedical context for systematic enrichment analysis

Kitani, A.; Zhang, B.; Himori, K.; Matsui, Y.

2026-08-20 bioinformatics 10.64898/2026.08.18.745318 medRxiv
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Glycan identification has advanced, but glycan structures remain difficult to translate into reproducible biomedical context because reusable glycan-level annotations are sparse. We present GlycoMeSH, a resource that links glycans to Medical Subject Headings (MeSH) through an inference model, a traceable association database and a glycan-set enrichment workflow. GlycoMeSH-BERT recovered ~60% of literature-derived associations at recall@30 and expanded open-vocabulary MeSH coverage beyond closed-label baselines, without higher per-prediction accuracy. At matched candidate counts, its predictions showed motif-level semantic agreement comparable to those baselines, independently of the training labels. GlycoMeSH-DB contains 789,627 associations between 26,954 glycans and 20,302 MeSH terms. GlycoMeSH-EA returned enriched MeSH terms for glycan sets from glycomics and glycoproteomics datasets. Each association represents a biomedical context rather than a validated mechanism, and retains its source PMID or prediction score for audit. GlycoMeSH supplies the missing, evidence-traceable annotation layer that makes glycan sets directly analyzable by enrichment across glycoscience datasets.

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A Cesium Chloride Gradient Ultracentrifugation-Based Method for the Isolation of DNA from Diverse Recalcitrant Plant Species for Nanopore Sequencing

Labbancz, J.; Dhingra, A.

2026-08-21 molecular biology 10.64898/2026.08.18.745475 medRxiv
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Developments in Nanopore sequencing have enabled telomere to telomere genomic assembly as a routine technique in genomic research. Nanopore DNA sequencing for genomic assembly is typically performed on native DNA molecules, making it particularly sensitive to the quality of input DNA, with contaminating molecules limiting data yields and reducing read quality. As pangenome analysis gains interest, particularly in non-model plant species which are often rich in inhibitory secondary metabolites, the development of methods which can improve the quality and throughput of nanopore sequencing is essential. Here we describe a method for isolation of total DNA from the leaf tissues of diverse Viridiplantae species. The initial lysis buffer consists of a modified CTAB buffer, incorporating dimethyl sulfoxide for the reduction of viscosity, which can be problematic in many plant DNA preparations. An organic extraction with 2-butoxyethanol is utilized to further extract phenolic compounds which may be sufficiently hydrophilic to evade chloroform extraction, while reducing aqueous phase volume. Further cleanup via cesium chloride (CsCl) ultracentrifugation is performed to minimize the carryover of residual contaminating macromolecules. Samples prepared using this method are of consistent high quality, even when extracted from challenging late season leaf tissue or secondary metabolite rich species. Sequencing results from samples prepared by this method outperform those obtained from typical modified CTAB DNA isolation techniques in both quantity and quality. We tested sequencing performance from Vitis DNA isolated using a modified CTAB method and Vitis DNA isolated using the CsCl ultracentrifugation-based method described here. DNA isolated via the method described here produced 83% more >Q10 sequence data (52.61 Gb vs. 28.8 Gb), resulted in a 60% greater read N50 despite more handling steps (32.78kb vs. 20.45kb), and resulted in a higher modal read quality (Q27 vs. Q24). The consistency of this method across diverse plant taxa suggests its use as a general method for DNA isolation prior to Nanopore sequencing and genomic assembly for diverse plant taxa.

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Impact of Reduced Chlorophyll Levels in Leaves on Soybean Yield, Seed Composition, Pod/Seed Photosynthesis, and Chlorophyll Levels in Pod and Seed Tissues

Jones, S. I.; Stutz, S. S.; Atalay, E.; Wang, Y.; Ort, D. R.; Cho, Y. B.

2026-08-19 plant biology 10.64898/2026.08.14.744892 medRxiv
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Soybean, a widely cultivated leguminous crop valued for its protein, amino acids, and oil, faces the challenge of maintaining protein levels, which have an inverse correlation with yield. Reducing leaf chlorophyll levels could increase seed protein levels without compromising yield; however, this is yet to be tested. Therefore, to understand the impacts of low chlorophyll mutations on soybean yield and seed composition, we screened and compared 25 low chlorophyll soybean mutants to their 11 dark green parents. PI548210 (Lincoln mutant) demonstrates a higher concentration of protein without affecting yield compared to its dark green parent PI548362 (Lincoln), suggesting it as a good candidate for further large-scale field trials. PI547555 (Y11/y11, Clark mutant) demonstrates a lower concentration of oil without impacting yield, alongside lower gross photosynthesis, but with chlorophyll levels in the pod and seed tissues that are comparable to its dark green parent PI548533 (Clark). These findings are consistent with the oil concentration of the soybean being influenced by pod and seed photosynthesis, which is correlated with pod height and row spacing. Chlorophyll levels in the leaf do not necessarily correlate with those in the pod and seed of low chlorophyll mutants, possibly due to substantially lower expression of chlorophyll synthesis genes in the pod and seed. SIGNIFICANCEO_LIPI548210 (Lincoln mutant), one of twenty-five low chlorophyll soybean mutants, demonstrates a higher concentration of soybean protein without affecting yield compared to its dark green parent (Figure 1 and Table 1). C_LIO_LIPI547555 (Y11/y11, Clark mutant), a low chlorophyll soybean mutant, demonstrates a reduced concentration of soybean oil without impacting yield, alongside lower gross photosynthesis in pod and seed tissues compared to its dark green parent (Figures 3 and Table 2). These findings suggest that the oil concentration of the soybean is influenced by pod and seed photosynthesis, which is in turn influenced by pod height and row spacing (Figure 2). C_LIO_LIChlorophyll levels in the leaf do not necessarily correlate with those in the pod and seed of low chlorophyll mutants, possibly due to substantially lower expression of chlorophyll synthesis genes in the pod and seed (Figure 5-6). C_LI O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=84 SRC="FIGDIR/small/744892v1_fig1.gif" ALT="Figure 1"> View larger version (55K): org.highwire.dtl.DTLVardef@4282dcorg.highwire.dtl.DTLVardef@9d565forg.highwire.dtl.DTLVardef@1918292org.highwire.dtl.DTLVardef@1359b1_HPS_FORMAT_FIGEXP M_FIG O_FLOATNOFigure 1.C_FLOATNO Two low chlorophyll mutants are as healthy as their dark green parents. Lincoln and its low chlorophyll mutant, left; Clark and its low chlorophyll mutant, known as Y11/y11, right. It can be seen by eye that the plants have low chlorophyll (light green/yellow leaves) but a similar growth habit to their dark green parents. See Supplemental Figures 1-4 for contrast, where low chlorophyll mutants are stunted in growth compared to their dark green parents. C_FIG O_TBL View this table: org.highwire.dtl.DTLVardef@657ec9org.highwire.dtl.DTLVardef@166e75borg.highwire.dtl.DTLVardef@df23c7org.highwire.dtl.DTLVardef@1a60124org.highwire.dtl.DTLVardef@194ed96_HPS_FORMAT_FIGEXP M_TBL O_FLOATNOTable 1.C_FLOATNO O_TABLECAPTIONComparison of seed yield, weight, seed composition between low chlorophyll mutants and their dark green parents. ANOVA is used with linear mixed model (random effect = block, fixed effect = variety). Least squares mean is used to compare. For yield and seed composition, N=4 blocks. For leaf chlorophyll (SPAD), N=40. Yield is average yield per plant (g). n.s. = not significant. C_TABLECAPTION C_TBL O_FIG O_LINKSMALLFIG WIDTH=179 HEIGHT=200 SRC="FIGDIR/small/744892v1_fig3.gif" ALT="Figure 3"> View larger version (26K): org.highwire.dtl.DTLVardef@7a368aorg.highwire.dtl.DTLVardef@192b8f0org.highwire.dtl.DTLVardef@1abb738org.highwire.dtl.DTLVardef@89e978_HPS_FORMAT_FIGEXP M_FIG O_FLOATNOFigure 3.C_FLOATNO Light response curve of low chlorophyll mutant (Y11/y11, PI547555) and its parent (Clark, PI548533). Rates of net and gross photosynthesis of low chlorophyll (white) and dark green parents (black) pods under field conditions. Each dot represents a value (n=4) {+/-}SE. We assumed that the seeds greatly inhibited the transmittance of light through the pod and used photosynthetic photon flux density for a single-side. C_FIG O_TBL View this table: org.highwire.dtl.DTLVardef@3f0528org.highwire.dtl.DTLVardef@16ba712org.highwire.dtl.DTLVardef@a5ab2aorg.highwire.dtl.DTLVardef@889254org.highwire.dtl.DTLVardef@3efa4f_HPS_FORMAT_FIGEXP M_TBL O_FLOATNOTable 2.C_FLOATNO O_TABLECAPTIONPod photosynthetic parameters for low chlorophyll mutant (Y11/y11, PI547555) and its parent (Clark, PI548533). Photosynthesis was measured 1 September through 15 September 2021 at the University of Illinois Energy Farm in Urbana, IL, USA. The statistical analysis was done using ANOVA with linear mixed model (alpha=0.05). N=4 {+/-} SEM for Clark and N=3 {+/-} SEM for Y11. C_TABLECAPTION C_TBL O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=130 SRC="FIGDIR/small/744892v1_fig2.gif" ALT="Figure 2"> View larger version (23K): org.highwire.dtl.DTLVardef@a36c26org.highwire.dtl.DTLVardef@1116c8forg.highwire.dtl.DTLVardef@ee5e61org.highwire.dtl.DTLVardef@1766712_HPS_FORMAT_FIGEXP M_FIG O_FLOATNOFigure 2.C_FLOATNO Low chlorophyll mutant (Y11/y11, PI547555) and its parent (Clark, PI548533) differ in concentration of seed oil, which interacts with height of pod and row spacing. The box plots show the median (central line), the lower and upper quartiles (box) and the minimum and maximum values (whiskers). The statistical analysis was done using ANOVA with linear mixed model (n=3 blocks, alpha=0.05). Least squares mean is used to compare. N.s., non- significant in the analysis. A. Concentration of oil in low chlorophyll mutant seeds from the upper canopy decreased by 4% compared to the dark green parent (18.2% vs 19%) while there was no difference between them in the seeds from the lower canopy (20.2% vs 20.6%). B. Schematic layout of 2013 field setting showing two different row spacings. C. Concentration of oil in low chlorophyll mutant decreased by 2% in 38cm spacing (21.4% vs 22%) while there was no difference in 19cm spacing (21.3% vs 21.7%) in 2013 field. C_FIG O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=162 SRC="FIGDIR/small/744892v1_fig5.gif" ALT="Figure 5"> View larger version (22K): org.highwire.dtl.DTLVardef@68e508org.highwire.dtl.DTLVardef@94a6ccorg.highwire.dtl.DTLVardef@152a187org.highwire.dtl.DTLVardef@1eae137_HPS_FORMAT_FIGEXP M_FIG O_FLOATNOFigure 5C_FLOATNO (greenhouse). Correlation between the level of leaf chlorophyll (x-axis: SPAD reading) and the level of immature pod or seed chlorophyll (y-axis, mg/g DW). Line represents the linear regression model. R-squared is a coefficient of determination, the percentage of the response variable variation that is explained by the linear model. Pod is labeled by the fresh weight of seeds it contained. A. Level of chlorophyll of 25-100mg pod (n=18). B. Level of chlorophyll of 100-200mg pod (n=17) . C. Level of chlorophyll of 25-100mg seed (n=17). D. Level of chlorophyll of 100-200mg seed (n=20). C_FIG O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=180 SRC="FIGDIR/small/744892v1_fig6.gif" ALT="Figure 6"> View larger version (28K): org.highwire.dtl.DTLVardef@167fd88org.highwire.dtl.DTLVardef@361472org.highwire.dtl.DTLVardef@786325org.highwire.dtl.DTLVardef@1b53855_HPS_FORMAT_FIGEXP M_FIG O_FLOATNOFigure 6.C_FLOATNO Levels of gene expression in chlorophyll synthesis pathway. A. CHL common pathway genes; Glutamyl-tRNA reductase (GluTR). Glutamate 1- semialdehyde aminotransferase (GSA-AT). ALA dehydratase (ALAD). Uroporphyrinogen III synthase (UROS). Uroporphyrinogen III decarboxylase (UROD). Protoporphyrinogen IX oxidase (PPO). B. Mg branch; Mg-chelatase (Mgch). Magnesium-protoporphyrin IX monomethyl ester cyclase (MPEC). Protochlorophyllide reductase (POR). 3,8-divinyl protochlorophyllide a 8-vinyl-reductase (4VCR). Heme pathway; Ferrochelatase (FECH). Heme oxygenase (HO). Phytochromobilin synthase (HY). Data come from Severin et al (2010). RPKM, reads per kilobase per million mapped reads. DAF, days after flowering. The source seed is experimental line A81-356022 which was generated by introgressing G. soja (PI468916) into G. max (A81-356022). C_FIG

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Method for modeling oviduct function and impact on embryonic development

Stephens, K. K.; Ahmad, V.; Silva, M. A.; Shifflett, M. K.; Mao, J.; Rizo, J. A.; Hunter, M. I.; Kelleher, A. M.; Winuthayanon, W.

2026-08-07 cell biology 10.64898/2026.08.06.743297 medRxiv
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Direct experimental analysis of the mammalian oviduct is constrained by limited tissue access and the short lifespan of ex vivo preparations. Extracellular matrix-embedded three-dimensional epithelial organoids provide longer-term in vitro models. However, their inward-facing apical surface and the absence of supporting stromal cells limit physiological studies of the oviduct, including ciliary activity and maternal-embryonic interactions. Here, we provide a step-wise protocol detailing the generation of mouse and human oviductal assembloids in which epithelial cells form an outward-facing (apical-out) layer around a stromal core. Epithelial and stromal cells from adult mouse oviducts or human Fallopian tubes are isolated, expanded separately, and subsequently aggregated in a rotational culture system. The protocol also outlines morphological and immunostaining criteria for confirming cellular organization, whole-mount detection of external cilia, measurement of ciliary beat frequency, and co-culture of mouse assembloids with preimplantation embryos. Mouse and human assembloids retained epithelial and stromal identity and displayed cilia at the accessible outer surface. In a proof-of-concept experiment, embryos co-cultured with the assembloids developed to blastocysts at a rate similar to that of in vivo-derived blastocysts. This reductionist system provides a straightforward and tractable model to investigate oviduct physiology and embryo-maternal communication while allowing direct manipulation and observation of the epithelial interface. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=148 SRC="FIGDIR/small/743297v1_ufig1.gif" ALT="Figure 1"> View larger version (50K): org.highwire.dtl.DTLVardef@1917a7borg.highwire.dtl.DTLVardef@41d7org.highwire.dtl.DTLVardef@e2bf98org.highwire.dtl.DTLVardef@90c9f3_HPS_FORMAT_FIGEXP M_FIG C_FIG SummaryThe protocol for generating mouse and human oviductal assembloids by combining epithelial and stromal cells for studying oviductal function in an in vitro setting.

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Site Specific Fluorescent Labeling via SpyTag SpyCatcher for Rapid Hybridoma Screening in Semi-Solid Medium

Guo, A.; Wei, M.; Wu, J.; Li, X.; Jiang, B.

2026-08-31 immunology 10.64898/2026.08.21.746134 medRxiv
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Hybridoma screening in semi-solid medium typically employs antigens labeled with visible fluorophores (e.g., FITC, AF488) to enable single-step identification of antibody-secreting clones. However, conventional chemical conjugation via NHS-esters or isothiocyanate groups frequently modifies lysine residues located within epitopes, potentially abrogating antibody recognition of these critical regions. Here, we describe a SpyTag SpyCatcher-based site-specific labeling strategy that circumvents epitope damage during semi-solid medium screening. A 16-amino-acid SpyTag was genetically fused to the C-terminus of the target antigen, enabling covalent conjugation to an sfGFP SpyCatcher fluorescent probe. In semi-solid medium supplemented with SpyTag-antigen and sfGFPSpyCatcher, positive hybridoma clones were readily identified by distinct fluorescent halos, whereas negative clones showed no detectable signal. Notably, the site-specific method yielded a significantly higher frequency of fluorescence-positive clones compared to the conventional AF488-labeled antigen method, suggesting that epitope preservation enhances screening recovery. Furthermore, this approach did not impair hybridoma growth or final clone positivity, offering a simple, rapid, and epitope-compatible method for monoclonal antibody screening.