Mix the dye solution according to the live/dead staining kit’s instructions. Many staining kits contain several chemicals which must be combined to create dye. Staining kits are also called “viability assay kits.”
Add one microliter of live/dead dye mixture per one milliliter of bacteria sample. For example, if you have 3 centiliters of bacterial sample, add 30 microliters of live/dead dye solution. Different live/dead solutions might require different levels of dye mixture, so read instructions thoroughly before adding dye.
Mix bacteria and dye for several minutes.
Place bacteria and dye mixture in a dark area, covered, at room temperature for about 15 minutes.
Pull one drop of bacteria/dye mixture into your dropper and place on glass slide.
Cover with slide coverslip.
Attach fluorescein longpass filter to your microscope, following the instructions on the filter. If you need help preparing the microscope, ask your lab instructor or lab assistant.
Place the slide in microscope, as per instructions for your specific microscope. Live bacteria appear to fluoresce (glow) green, while dead fluoresce red.