Single Cell Sorting for Clonal Cell Line Development

CHO cells were prepared in a single-cell suspension using Cell Suspension Buffer (PBS, 1% BSA, 1mM EDTA). Viable cells were identified by a lack of propidium iodide (PI) staining. Viable cells were gated on scatter to avoid debris. Doublet-discrimination was performed and singlets were selected for sorting. The Cell Suspension Buffer was used as the sheath buffer. Live, debrisfree, single CHO cells were sorted and dispensed into 96-well plates. The number of cells per well were evaluated using a NyONE plate imager where we observed 80% of the wells to have a single cell with 50% outgrowth to form colonies. The gentle sorting of the WOLF results in improved viability, higher outgrowth, and improved workflow efficiency.