Abstract: A method of inducing latency in Mycobacterium permits preparation of an in vitro model system of latent mycobacterial infection. Latency is induced in a pure culture of Mycobacterium by exposing it to multiple stress conditions, including a low nutrient culture medium without glycerol, a low pH, a relatively high level of carbon dioxide and a relatively low gas phase oxygen level. An in vitro model of mycobacterial infection employs macrophages induced from THP1 cells which are then infected with Mycobacterium. The infected macrophages are grown under hypoxic conditions to induce latency in the mycobacteria. The in vitro model of infection is useful in evaluating compounds for activity against latent mycobacteria.