Dried seminal stains on clothes identified by

A. Spectrometry
B. UV rays
C. Infrared rays
D. LASER.

Answer: B. UV rays.


Explanation:

• Seminal stains have to be detected in criminal cases of rape, sexual murder of the female, sodomy, bestiality and in civil cases of disputed paternity.
• Differential diagnosis: Seminal stains, 
•                                       starch, 
•                                       pus, 
•                                       leucorrhoeal discharge,
•                                       nasal discharge and 
•                                       egg albumin.

• A fresh stain on a non-absorbent material appears translucent.
• Seminal stains are examined under filtered Ultraviolet light, they show a florescence of a bluish-white colour (due to choline).
• Fluorescence depends on choline of semen.