2.5.1. XTT reduction assay

The antimicrobial activity of Sb-AgNP was analyzed with XTT reduction assay (Pierce et al., 2008). 1 × 10⁶/ml of resistant and sensitive candida strains were individually seeded onto the sterile 96 well flat bottomed culture plates and incubated for 24 h. After 24 h incubations the candid biofilms were treated with 30 µg/ml of Sb-AgNP, standard antifungal drug fluconazole and the plates were incubated for 4 h at 37 °C. The media was then removed and the wells were rinsed thrice with distilled water to remove non adherent cells. The treated and untreated biofilms were subjected XTT reduction assay. XTT solution was prepared by dissolving 1 mg of XTT in 1 ml of PBS and the solution was filtered and stored. 0.4 mM menadione solution was freshly prepared before the assay. To the wells 158 µl of PBS, 40 µl of XTT and 2 µl of menadione was added and the plates were incubated in dark for 2 h. After incubation period 100 µl solution from each well was transferred to a new 96 well plates and the absorbance of the solution was measured 492 nm using microtitre plate reader.