To determine the germ content, various methods adapted to the respective product matrix are available. Standard ablations on plates or Schrägagar tubes provide inexpensive semi-quantitative statements, which are often sufficient.

As a more precise system, a spiral plater is used which provides reliable numbers in the range of about 10 colony-forming units per ml (CFU / ml) to about 10⁶ CFU / ml in the expected number of germ counts.

For the investigation of nearly sterile products, especially water, a sterile filtration process is also used. In the case of typical systemic germs, in addition to the broadband standard nutrient media (CASO, malt extract) it is also possible to work with selective nutrient media, which often already allow a rough identification of the germ flora.