In the laboratory examination of a stain suspected to contain semen, the Florence test produces characteristic crystals. These crystals are composed of:

• A Spermine picrate
• B Choline iodide
• C Choline picrate ✓
• D Spermine phosphate

Explanation

The Florence test relies on addition of Lugol's iodine solution to the stain extract, producing dark brown rhombic crystals of choline picrate; it is a presumptive, not confirmatory, test for semen because choline occurs in other body tissues and fluids. Spermine picrate crystals are formed in the Barberio test, a different presumptive test. Choline iodide and spermine phosphate are not the products of any standard semen crystal test.

Reference: The Essentials of Forensic Medicine and Toxicology, K.S. Narayan Reddy, 34th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.