system
Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
In a case of suspected poisoning, the preservative used for vitreous during autopsy is:
assistant
The correct answer is  Fluoride should be added to urine, CSF, and vitreous humour if alcohol estimation is required, and also to samples for analysis for cocaine, cyanide and CO. Sodium or potassium fluoride should be used for preserving blood. Ref: The essentials of forensic medicine and toxicology by Dr K S Narayan Reddy, 27th edition, Page 111.