SunCatcher: Clonal Barcoding with qPCR-Based Detection Enables Functional Analysis of Live Cells and Generation of Custom Combinations of Cells for Research and Discovery

Over recent decades, cell lineage tracing, clonal analyses, molecular barcoding, and single cell "omic" analysis methods have proven to be valuable tools for research and discovery. Here, we report a clonal molecular barcoding method, which we term SunCatcher, that enables longitudinal tracking and retrieval of live barcoded cells for further analysis. Briefly, single cell-derived clonal populations are generated from any complex cell population and each is infected with a unique, heritable molecular barcode. One can combine the barcoded clones to recreate the original parental cell population or generate custom pools of select clones, while also retaining stocks of each individual barcoded clone. We developed two different barcode deconvolution methods: a Next-Generation Sequencing method and a highly sensitive, accurate, rapid, and inexpensive quantitative PCR-based method for identifying and quantifying barcoded cells in vitro and in vivo. Because stocks of each individual clone are retained, one can analyze not only the positively selected clones but also the negatively selected clones result from any given experiment. We used SunCatcher to barcode individual clones from mouse and human breast cancer cell lines. Heterogeneous pools of barcoded cells reliably reproduced the original proliferation rates, tumor-forming capacity, and disease progression as the original parental cell lines. The SunCatcher PCR-based approach also proved highly effective for detecting and quantifying early spontaneous metastases from orthotopic sites that would otherwise have not been detected by conventional methods. We envision that SunCatcher can be applied to any cell-based studies and hope it proves a useful tool for the research community.