Biofilm formation in the msa mutant in microtiter plates. The wild type strain COL, the msa mutant and the complemented msa mutant were grown in TSB supplemented with NaCl and glucose. Cultures were incubated for 6, 12 and 24 hours in the wells of microtiter plates with pre-coating with plasma proteins. Biofilm was quantitated by staining with crystal violet and elution with ethanol as described in text. All values have been normalized to wild type levels which were arbitrarily set as 100%.