Figure 12: Chitosan binding to C. albicans ATCC 10231 at different concentration ratios of the polymer. Cells (12.5 mg·mL−1) were incubated in 10 mM MES-TEA buffer, pH 6.0, and 20 mM glucose; or 20 mM glucose and 2% bactopeptone; or 20 mM glucose and 1% yeast extract or YPD medium only; each one with variable amounts of chitosan in μg·mL−1 as indicated, in a final volume of  1 mL for 10 min at 30°C. Then, they were centrifuged (1625 g) and the remaining chitosan in the supernatant was measured by means of its fluorescence change in bicine-TEA 10 mM pH 8 with 10 μM calcofluor at 350–440 nm (a). Another experiment was performed without cells, with or without centrifugation (b).