The antimicrobial activities of different natural dyes were tested against five bacterial strains and five fungal clinical isolates using disk diffusion method (Naz et al., 2010; Han and Yang, 2005).
The culture plates were inoculated with 100l of standardized inoculums of each fungal and bacterial strain and spread with sterile swabs.
Discs are 6mm sizes and put into agar plates containing the fungal and bacterial inoculums. 50l of the natural dyes were loaded into the discs of the culture plates. After inoculation the plates were incubated for 24 h at 37 ◦C, the plates were observed.
If antifungal and antibacterial activity was present on the plates, it was indicated by an inhibition zone surrounding the disc containing the natural dye.
The zone of inhibition was measured and expressed in millimeters. Antimicrobial activity was recorded if the zone of inhibition was greater than 6mm.