FIG 5.

Evaluation of biofilm production with scanning electron microscopy for S. mutans wild-type strain UA159 and mutant strains deficient in primary K⁺ transport systems. (A) Biofilms were grown on microtiter plates in MMGK supplemented with various concentrations of KCl (0 to 150 mM). After a 20-hour incubation, supernatant was removed and biofilms were dried and stained with 0.1% crystal violet dye. The experiment was repeated at least three times using triplicate wells each time. Representative photographs are shown. (B) Biofilms were grown on glass coverslips placed in microtiter plates containing MMGK supplemented with 5 mM. Following a 20-hour incubation period, biofilms were dehydrated and further processed for SEM. Representative micrographs are shown.