A Convection-Free Apparatus for Low Force and High Efficiency Centrifugation

Centrifugation is a common technique for material separation. Most biological materials are separated under a relatively strong centrifugal force. Despite several reports highlighted the impact from centrifugal force on the separated materials, low force centrifugation typically results in low efficiency of separation and may not be achievable from the traditional centrifugation apparatus. Here, we present a novel apparatus for separating materials under low centrifugal force with high efficiency. Compare to the traditional apparatus, the design of this apparatus minimizes the convection during centrifugation. Using homogeneous polystyrene particles, we confirmed that the centrifugation process is essentially convection-free. Separation of human blood cells indicated that, under a fixed centrifugal force, less than half of the centrifugation time is required compared to the traditional apparatus. The isolated human peripheral blood mononuclear cells have higher viability and can afford multiple centrifugations without impacting cell viability. Additionally, this new apparatus has a higher resolution to separate materials by size and is sensitive to detect size heterogeneity. This apparatus provides a new opportunity for efficient centrifugation under low centrifugal force and for a systematic evaluation of the impact from centrifugal force on the quality of separated materials.