In postmortem chemistry, the preferred specimen for estimating antemortem blood glucose and urea levels is vitreous humour rather than peripheral blood because:
- A Vitreous is less susceptible to putrefactive bacterial contamination and postmortem redistribution ✓
- B Vitreous always perfectly reflects antemortem serum values without any postmortem change
- C Peripheral blood has no glucose or urea postmortem and vitreous is the only remaining source
- D Vitreous collection is technically easier and requires no special preservative
Correct answer: A. Vitreous is less susceptible to putrefactive bacterial contamination and postmortem redistribution
Explanation
The vitreous humour is anatomically isolated in a closed compartment, protected by the sclera, and has no direct access to gut bacteria or cardiac blood. This makes it highly resistant to postmortem redistribution (the movement of drugs/analytes from the GI tract or viscera into blood after death) and bacterial fermentation. While vitreous values still change postmortem (e.g., potassium rises), the changes are more predictable and consistent than peripheral blood. It does not perfectly mirror antemortem values; option B is incorrect.
Reference: The Essentials of Forensic Medicine and Toxicology (Narayan Reddy), 34th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.