Читать книгу Analytical Food Microbiology - Ahmed E. Yousef - Страница 55

“Plating” refers to the process of transferring and incorporating the sample to be analyzed, or its dilutions, into a suitable agar medium in a Petri plate. When the agar medium is poured and solidified in the Petri plate in advance, incorporation of a small volume of the sample dilution is done by spreading and the process is described as “spread‐plating.” Alternatively, a larger amount of the sample, or its dilution, may be dispensed first in an empty Petri plate into which warm molten agar is poured, and plate contents are mixed. This process is known as “pour‐plating.” Analyzing a food for a given microorganism may necessitate using pour‐plating or spread‐plating, but in other circumstances the two methods can be used interchangeably. Note that these two plating methods require different dilution schemes.