Viable plate count

Definition

Viable plate count is a microbiological technique used to estimate the number of living bacteria in a sample by counting the number of colony-forming units (CFUs) that grow on an agar plate. It provides a quantitative measure of microbial population size.

5 Must Know Facts For Your Next Test

1. Viable plate counts only measure live microorganisms capable of forming colonies.
2. The method involves serial dilution of the sample and plating onto agar media.
3. Results are typically expressed as CFU per milliliter (CFU/mL) for liquid samples or per gram for solid samples.
4. Incubation time and temperature are critical factors influencing colony formation and accurate counts.
5. This technique cannot distinguish between different types of bacteria present in mixed cultures without selective media.

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Related terms

Serial Dilution: A stepwise dilution of a substance in solution, often used to reduce a dense culture to a more usable concentration.

Colony-Forming Unit (CFU): A unit used to estimate the number of viable bacteria or fungal cells in a sample.

Agar Plate: A petri dish filled with agar used as a growth medium for microorganisms.