Flow Cytometry (FACS) Safety

Fixation of cells after staining and before running them through a flow cytometer is highly recommended if there are any questions about the pathogenicity of the cells involved. Since there are real concerns about the potential pathogenicity of all living cells, fixation after staining is always recommended unless the cells will be sorted and cultured afterward or unless you need to look at membrane integrity of the cells as a measure of viability.