Analysis of biofilm growth
Crystal violet staining was performed as described previously (McAuliffe
et al., 2006). Biofilms grown on glass coverslips and in microtitre
plates were rinsed briefly in PBS to remove non-adherent cells and
stained with 0.5% crystal violet solution for 30 min. Biofilms were then
washed profusely in dH2O before being left to dry at
room temperature for 30 min. Coverslips were broken into smaller pieces
using sterile forceps and 1 ml 100% ethanol was added to solubilize the
crystal violet. Solubilization of the crystal violet in stained biofilms
was implemented by adding 200 ml of 100% ethanol onto the microtitre
plates. Biofilm production was quantified by measuring the absorbance (560
nm) of 100 ml of the solubilized crystal violet in a microtitre plate.