Final answer:
Quality-control tests in labs, including turbidity measures for bacterial cultures, are essential for ensuring experiment accuracy, testing disinfectant efficacy, and when using fluorescence microscopy, fluorochromes are required to visualize specific components of a specimen.
Step-by-step explanation:
Quality-control tests in laboratories are performed daily to ensure the accuracy and reliability of experimental results. For the specific question regarding turbidity measures of bacterial cultures, it is important to measure the transmission of light through a control tube with only broth in it because this serves as a baseline or blank to calibrate the spectrophotometer. This allows for the correction of any light absorbance due to the broth itself rather than the bacteria, ensuring that subsequent turbidity measurements reflect only the contribution of bacterial growth.
In terms of methods to measure the concentration of bacterial contamination in processed products like peanut butter, total plate count (B) is commonly used. This technique allows for the growth of bacteria on a culture medium so that they can be counted as colony-forming units (CFUs). Turbidity measurement (A) could also be used to assess bacterial growth indirectly by measuring the cloudiness of a sample but may not be as precise as a total plate count in certain contexts.
Disinfectant solutions used in clinical settings are tested to verify their efficacy. This involves standardized tests that compare the performance of the disinfectant against known standards to ensure it is effectively killing or inhibiting microbial growth.
Lastly, when using a fluorescence microscope, fluorochromes are essential because they bind to components of the specimen and fluoresce when illuminated with light of a specific wavelength. This fluorescence allows for the visualization of structures or molecules of interest within the sample, which would otherwise be invisible under normal light conditions.