LOWENSTEIN JENSEN COOL is a rich medium containing all the ingredients necessary for mycobacterial growth. Solidifying the medium without heating after adding eggs gives additional richness to the medium. Egg albumin binds to toxic fatty acids released during mycobacterial growth. Malachite green, which gives the medium its green color, inhibits the growth of many different types of bacteria and creates a selective medium for mycobacteria that are resistant to this dye.
