Description
Drigalski Lactose Agar is a selective differential medium for isolating Enterobacteriaceae and non-fermenting Gram-negative bacilli from clinical specimens.
Deoxycholate, thiosulfate and crystal violet inhibit Gram-positive organisms. Lactose fermentation changes bromothymol blue, producing yellow colonies for fermenters and blue-grey to green colonies for non-fermenters.
Clinical samples are spread across the agar and incubated aerobically at 35 ± 2°C for 18–24 hours. Colony colour and morphology support presumptive differentiation.
