Estimation of the protein content on the film surface can be a
good option to confirm bacterial adhesion to film. Colonized HIPS
film samples were collected from the liquid culture broth at regular
intervals of time and boiled in 5 ml 0.5 M NaOH for 30 min.
After required time of incubation, the suspension was centrifuged
and the pellets and supernatant were separated. The steps were
repeated and the supernatants obtained were pooled and protein
content was estimated through Bradford’s assay (Sedmak and
Grossberg, 1977).