Centrifuge again at 400g and discard supernatant. Count cells and resuspend at an
appropriate concentration, which will vary with sorter used but will be in the range
of 1 × 106–1 × 107 per mL. The final suspension medium will depend on the cell
types to be sorted. In general, a low protein concentration is recommended because
this will lead to less cell clumping although the addition of 5 mM EDTA (ethylenediaminetetraacetic
acid) will also help this.