Löwenstein–Jensen medium

The Löwenstein–Jensen medium, more commonly known as LJ medium, is a growth medium specially used for culture of Mycobacterium species, notably Mycobacterium tuberculosis. The Löwenstein–Jensen medium, more commonly known as LJ medium, is a growth medium specially used for culture of Mycobacterium species, notably Mycobacterium tuberculosis. When grown on LJ medium, M. tuberculosis appears as brown, granular colonies (sometimes called 'buff, rough and tough'). The medium must be incubated for a significant length of time, usually four weeks, due to the slow doubling time of M. tuberculosis (15–20 hours) compared with other bacteria. The usual composition as applicable to M. tuberculosis is: