What is the primary purpose of the Pour Plate Method?

The primary purpose of the Pour Plate Method is to dilute and grow individual colonies. This technique involves mixing a microbial sample into molten agar and then pouring it into a Petri dish, allowing the mixture to solidify. As the agar solidifies, bacterial cells become trapped within the medium, where they can grow into colonies throughout the agar. This allows for the growth of both aerobic and anaerobic bacteria, as the colonies can develop below the surface of the agar as well as on the surface.

Additionally, the Pour Plate Method enables a more uniform dispersion of cells throughout the medium, which is particularly useful for estimating the total viable count of microorganisms in a sample. By examining the resulting colonies, one can determine the number of viable organisms present in the original sample based on dilution factors.

Options that suggest isolating bacteria on the surface only or that involve treating bacteria with antibiotics are not aligned with the methodology or purpose of the Pour Plate Method. Instead, the core focus of this method is indeed on dilution and the growth of bacteria into individual, countable colonies throughout the agar medium.