Microtiter plate assay for biofilm formation. Strains SA113 and 10833 and their isogenic isaB deletion mutants were screened for their ability to form biofilms in different media; TSB, TSB+1% glucose and 3.5% NaCl, BHI, BHI+1% glucose, LB, or LB+1% glucose. A. Safranin-stained biofilms and B. Average OD595 nm values of 8 wells from three separate experiments (24 values) of solubilized safranin-stained biofilms. Deletion of isaB did not reduce biofilm formation under any conditions tested but there was a statistically significant increase in OD595 nm in the absence of isaB in LBG.