Petrifilm ( Petrifilm ™ Corporation 3M ) - a ready-made test for the quantification of microorganisms . Used as an alternative to classic Petri dishes .
Petrifilm contains a ready-made nutrient medium, a gel, soluble in cold water, which solidifies at room temperature. The composition of the medium also includes a tetrazolium indicator, which facilitates the counting of colonies on petrifilm and chromogenic substrates, which allow revealing characteristic biochemical activities.
When adding the test sample (raw materials, products or swabs) or a water sample, a dense nutrient medium is formed on which the number of microorganisms can be counted.
Various chromogenic substrates are used to detect E. coli (β-glucuronidase), yeast / mold (phosphatase), BCIP, BCIG, DNAase (Staph.aureus).
A grid is applied to the surface of the petrifilm that facilitates colony counting. Petrifilms retain sterility thanks to a covering outer film
Defined Parameters
- TMP, Coliforms, Coliforms and E.coli, Enterobacteria, Yeast and Molds, Staphylococcus aureus, Listeria
Progress
- Pipette 1 ml of test sample (or dilution)
- Incubate in thermostat
- Take into account the results (count the number of colonies) manually or automatically using the Petrifilm Reader (Petrifilm ™ Plate Reader)
Benefits
- Ready-made tests (no need to prepare media and pour them into cups)
- Shortened study time
- Simple seeding procedure
- Save time and effort
- Reliable, accurate, reproducible method
- Long shelf life of tests (1-1.5 years) compared with ready-made nutrient media
- Automatic accounting of results. The Petrifilm Reader (Petrifilm ™ Plate Reader) allows you to quickly (in just 4 seconds) automatically record the number of colonies grown on the petrifilm.