Viable plate count is the direct method of microbial growth measurement based on the concept that living cells give rise to visible colonies which can be counted in units of colony-forming units per milliliter (CFU/mL); however this count is often an underestimate of the actual number of viable cells. 

- Plate Count 
- Serial Dilution
- Most Probable Number (MPN)

Direct Methods for Measuring Microbial Growth 

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Microbiology covers the scope and sequence requirements for a single-semester microbiology course for non-majors. The book presents the core concepts of microbiology with a focus on applications for careers in allied health. The pedagogical features of the text make the material interesting and accessible while maintaining the career-application focus and scientific rigor inherent in the subject matter. Microbiology’s art program enhances students’ understanding of concepts through clear and effective illustrations, diagrams, and photographs.

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Plate Count

Serial dilution is a method of direct microbial growth measurement that dilutes an original culture in order to obtain a smaller, more countable number in order to calculate the  colony-forming units per milliliter (CFU/mL). The goal is to obtain CFUs between 30-300, and then proceeding to either the pour or spread plate methods of inoculation. 

Serial Dilution 

The Most Probable Number (MPN) is a statistical estimation of viable cells detectable growth in a sample based on observable physical characteristics such as color or turbidity. 

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