Antifoams do not affect cell viability. Viable cells without antifoam (A) and with 0.6% Antifoam A (as a representative example; B) are shown. Population A, which is not cellular, comprises events that are related to electronic and particulate noise. Population B comprises cells with enhanced green fluorescence due to the expression of GFP. Population C is where any dead cells (stained red with propidium iodide) would be observed.