Which test is used to detect the presence of seminal fluid?

• A. Acid phosphate test.
• B. Kastle-Meyer test.
• C. Luminol.
• D. To detect the presence of seminal fluid.

Answer: (D)

The main idea here is that semen has a distinctive enzyme that can be detected with a dedicated test. The acid phosphatase test targets acid phosphatase, an enzyme produced in high amounts by the male reproductive tract, especially the prostate. If semen is present on a stain, this enzyme acts on the substrate used in the test and produces a visible color change, giving a presumptive indication of seminal fluid.

Kastle-Meyer and Luminol are both designed for blood detection. Kastle-M Meyer relies on a peroxidase-like activity typical of blood, while Luminol chemiluminesces in the presence of blood. They’re not specific for semen and can be misleading in mixed or non-blood samples. The remaining option isn’t a test at all—it's a restatement of what’s being looked for, not a method to detect it. So the acid phosphatase test is the appropriate choice for detecting seminal fluid.