Which of the following tests could be performed on a blood sample to better identify an individual in a microbiological context?

• A. Measuring blood glucose levels
• B. Catalase test to detect enzyme activity
• C. Gram staining to determine cell wall type
• D. Polymerase chain reaction (PCR) for genetic profiling

Answer: (D)

Verified step by step guidance

1. Understand the goal: The problem asks which test can be used on a blood sample to better identify an individual in a microbiological context, meaning we want a method that can provide specific identification at the genetic or molecular level.
2. Evaluate each option: - Measuring blood glucose levels is a biochemical test related to metabolism, not identification of microorganisms or individuals. - Catalase test detects the presence of the catalase enzyme in bacteria, useful for differentiating bacterial species but not for identifying an individual from a blood sample. - Gram staining classifies bacteria based on cell wall properties but does not provide individual-specific information.
3. Recognize that Polymerase Chain Reaction (PCR) amplifies specific DNA sequences, allowing for genetic profiling. This technique can detect unique genetic markers in the blood sample, making it highly suitable for identifying an individual or specific microorganisms.
4. Recall that PCR is widely used in microbiology and forensic science for precise identification because it targets DNA sequences unique to the organism or individual.
5. Conclude that among the options, PCR is the most appropriate test for genetic profiling and individual identification from a blood sample.