Assistant Laboratory Animal Technician (ALAT) Practice Exam

How does a RODAC plate test the effectiveness of a sanitization program?

1. By measuring water temperature

2. Through microbial culture and observation

3. Using color indicators for pH levels

4. By assessing noise levels in the facility

The correct answer is: Through microbial culture and observation

A RODAC (Replicate Organism Detection and Counting) plate is specifically designed to evaluate the effectiveness of a sanitization program by providing a means to culture and observe microorganisms present on surfaces. When a RODAC plate is inoculated with a sample taken from a cleaned surface, any microorganisms that are present will grow on the nutrient medium of the plate. The results are obtained by counting the colonies that form after incubation, which directly indicates the microbial load on that surface. A lower number of colonies suggests that the sanitization process is effective in reducing microbial contamination, while a higher number might indicate that the cleaning and sanitization protocols are not adequate. This method is widely used in facilities that require stringent hygiene practices, like laboratories and animal housing areas, as it provides a practical and direct assessment of the sanitation status of surfaces. In contrast, measuring water temperature, using color indicators for pH levels, or assessing noise levels in the facility do not provide relevant information about microbial contamination or the effectiveness of sanitization.