Figure 1. Fluorescent micrograph of Mtb detected by IF and AR in culture.

Mtb was detected by IF (A,D), AR (B,E) and combined IF-AR (C,F) in culture grown to stationary phase (A–C) and culture grown under hypoxic conditions (D–F). Culture was smeared on a poly-L-lysine coated slide and fixed with paraformaldehyde. Rabbit polyclonal antibody against whole Mtb cell lysate was applied for 1 hour at room temperature and detected using an Alexafluor 488 labeled secondary antibody (green). Slides were then stained with AR (orange/red) for 30 mins then destained. Pictures were taken using FITC and TRITC filters at 400× magnification. Bacilli seen here are mostly single cells but clumps of varying sizes are common.