96-Well Biofilm Assay

Static biofilm growth with a crystal violet readout.

6 steps · Microbiology · Biofilm

1. 1. Prepare the growth medium

   Compound the medium and confirm it is at room temperature before inoculation.

2. 2. Dilute the overnight culture

   Normalise the overnight to a working density in fresh medium before plating.

3. 3. Seed the plate

   Dispense the diluted culture into each test well. Leave the outer wells as medium-only blanks.

4. 4. Static incubation

   Incubate without shaking. Do not disturb the plate — agitation strips the biofilm.

5. 5. Wash and stain with crystal violet

   Invert to discard planktonic cells, wash gently, then stain the adherent biomass.

6. 6. Solubilise and read A550

   Solubilise the bound stain, then read absorbance. Blank against the medium-only wells.