Crystal Violet Cell Staining
Crystal violet binds to cell nuclei and gives absorbance readings proportional to cell counts at 595 nm.
1. After finishing reading the absorbance at 450 nm, wash the plate twice with 200 μl of Wash Buffer and
twice with 200 μl of 1x PBS for 5 minutes each. Tap the plates on paper towel to remove the excess liquid.
Let plate air dry for 5 minutes at room temperature.
2. Add 50 μl of crystal violet solution to each well, incubate for 30 minutes at room temperature on the
shaker. Note: Crystal violet is an intense stain. Avoid contact with skin and clothing.
3. Flick the plate to remove crystal violet solution, rinse the plate by filling the wells with running tap water,
and wash the plate with 200 μl of 1x PBS 3 times, 5 minutes each with gently shaking on the shaker.
4. Add 100 μl of 1% SDS into each well and incubate on the shaker at room temperature for 1 hour.
5. Read absorbance at 595 nm with microplate reader. If absorbance is too high, the solubilized crystal
violet solution can be diluted 10 times with H2O on a separate 96-well plate.