Question

What causes seminal stains to fluoresce under ultraviolet light ?

• A. Diasmin salts
• B. Acid phosphatase
• C. Spermatozoa
• D. Flavin

Hint:

Seminal stain detection: UV light → Fluorescence due to Flavin compounds.

Answer 1

The Correct Option is D

Concept: Seminal stains are often detected at crime scenes using ultraviolet (UV) light. Certain chemical components present in semen exhibit fluorescence when exposed to UV radiation.

Step 1: Understanding fluorescence.
Fluorescence occurs when a substance absorbs UV light and emits visible light. This property is used in forensic detection of biological stains.

Step 2: Role of flavins.
Flavins are naturally occurring compounds present in semen. These compounds fluoresce under UV light, producing a characteristic glow that helps investigators locate seminal stains.

Step 3: Evaluating other options.

• Diasmin salts – Not responsible for fluorescence.
• Acid phosphatase – Used for chemical testing, not fluorescence.
• Spermatozoa – Do not cause fluorescence.

Step 4: Final evaluation.
Thus, flavins are responsible for fluorescence under UV light. Final Conclusion:
Hence, the correct answer is (4).