Which of the following method is used to detect semen stains on clothes?
**Core Concept**
The detection of semen stains on clothes involves the identification of specific enzymes and proteins present in semen. Semen contains the enzyme choline esterase, which hydrolyzes choline esters, and also contains the protein prostate-specific antigen (PSA).
**Why the Correct Answer is Right**
The correct method for detecting semen stains on clothes involves the use of the Kastle-Meyer test. This test is based on the principle that semen contains the enzyme choline esterase, which can hydrolyze choline esters. The test involves applying a solution containing phenolphthalein to the suspected semen stain. If the stain is positive, the phenolphthalein will turn pink or red in the presence of the enzyme. This reaction is specific to semen and is not typically seen in other bodily fluids.
**Why Each Wrong Option is Incorrect**
**Option A:** Luminol is a chemical used to detect bloodstains, not semen stains.
**Option B:** The Kallikrein-kinin system is involved in the regulation of blood pressure and is not used to detect semen stains.
**Option C:** Acid phosphatase is an enzyme found in various bodily fluids, including semen, but it is not used as a specific test for semen stains.
**Clinical Pearl / High-Yield Fact**
It's worth noting that the Kastle-Meyer test is not 100% specific for semen and can produce false positives in the presence of certain substances. Therefore, it should be used in conjunction with other tests and in the context of a thorough investigation.
**Correct Answer: C. Kastle-Meyer test**