[Fluorescent test of mycoplasma colonies by agar diffusion technique (author's transl)].

An agar diffusion test to directly stain mycoplasma colonies using a new fluorochrome 4,6-diamidino-2-phenyl-indol (DAPI) is described. Next to a colony in question a well is punched into the agar and filled with DAPI. 30 min later the colonies in the diffusion zone show a light yellow - light green fluorescence. Due to the high affinity of DAPI to DNA it is easily possible to distinguish between granular mycoplasma colonies and unspecific substances e.g. proteins and lipids from clinical material.