How do I determine the dilution factor?
The formula for dilution factor (or DF for short) is as follows: DF = (final volume of cells + stain)/(initial volume of cells). For example, If you mix your sample 1:1 with AO/PI, you’ll need to add 20 uL AO/PI to 20 uL cells, for a total of 40 uL. So, DF = ( 40 uL)/(20uL cells) = 2. If you choose to dilute your cells prior to adding stains, you’ll also need to account for this in your DF. Use the same formula, except now it looks something like this: DF (final volume of cells & diluent)/ (initial volume of cells). For example, if you dilute 20 uL of your cells in 40 uL of media, DF = (60uL)/(20uL) = 3. To account for both stain and sample dilution prior to staining in this case, you would multiply these two dilution factors to get a value of DF=6.