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bioRxiv · 10.1101/2020.07.27.223917

CelLEVITAS: Label-free, rapid sorting and enrichment of live cells via magnetic levitation

Chin, E. K.·Grant, C. A.·Ogut, M. G.·Cai, B.·Durmus, N. G.
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Abstract

Sorting methods that remove non-viable cells and debris, while retaining a high yield of viable cells, are crucial for many applications in biotechnology, genomics, tissue engineering and medicine. However, a significant challenge is gentle sorting of these different cell states based on very minute differences in density and magnetic signatures, without relying on any labels, tags or markers. Here, a new magnetic levitation-based technology, CelLEVITAS, is developed for the label-free sorting and enrichment of live cells. This work reports the first use of magnetic levitation for sorting of viable and non-viable cells within a microfluidic device and demonstrates extremely effective removal of dead cells and debris from heterogeneous samples. First, the levitation conditions for separating viable and non-viable cells under a magnetic field were fine-tuned. Levitation trajectories of live and dead cell states were then monitored in real-time, as cells magnetically focused to their corresponding levitation bands. CelLEVITAS successfully sorted and enriched live cells from a variety of input cell concentrations (100-200,000 cells/mL) and a variety of input purities (10-50%) into consistently high output purities (>80%). This method is sensitive, does not impair cell viability during sorting, and significantly increases the input sample viability up to 7-fold. Overall, this new magnetic levitation-based sorting strategy drastically reduces the processing time to a single-step, 30-minute sorting protocol and eliminates the manual pre-processing and labeling steps that are required for traditional flow cytometry techniques.

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Chin, E. K., Grant, C. A., Ogut, M. G., Cai, B., Durmus, N. G.. 2020-07-29. CelLEVITAS: Label-free, rapid sorting and enrichment of live cells via magnetic levitation. https://doi.org/10.1101/2020.07.27.223917

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