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Asked by: Rafayel Spek
medical health infectious diseasesHow do you count bacterial growth in a Petri dish?
Use the formula: [Number of colonies counted]× 10 × [how many times the sample must be multiplied toget to the original concentration: for example, 105] =Number of colony forming units (CFU) per milliliter of startingculture. This is the bacterial growth in yourpetri dishes.
Keeping this in consideration, how do you measure bacterial growth in a Petri dish?
The easiest way to measure bacterial growth is toput your sample on a clear glass plate under a microscope and counthow many bacteria cells there are. Alternatively, you canmeasure turbidity, which is the amount of bacteria inyour sample.
how do you count bacterial growth?
The bottom sample is a mixed culture. There are avariety of ways to enumerate the number of bacteria in asample. A viable cell count allows one to identify thenumber of actively growing/dividing cells in a sample. The platecount method or spread plate relies on bacteriagrowing a colony on a nutrient medium.
Bacteria. Each distinct circular colonyshould represent an individual bacterial cell or group thathas divided repeatedly. Being kept in one place, the resultingcells have accumulated to form a visible patch. Most bacterialcolonies appear white, cream, or yellow in color, and fairlycircular in shape.