What component does Small Particle Reagent adhere to in fingerprint deposits?

Small Particle Reagent (SPR) is specifically designed to adhere to the fatty components found in fingerprint deposits. Fingerprints are composed of a mixture of substances, primarily sweat and sebum, the latter of which contains lipids and oils. These fatty materials are the primary binding sites for the particles in the SPR solution during the development process.

When SPR is applied to a surface where latent fingerprints are suspected, the small particles cling to these fatty components, resulting in a visual contrast that allows for the identification of the fingerprint. This technique is particularly useful on non-porous surfaces, where traditional fingerprinting methods may be less effective.

While fingerprints also contain proteins, salts, and water, the unique interaction of SPR with fats makes it an essential tool for enhancing and visualizing latent prints, highlighting the importance of targeting specific components in forensic fingerprint analysis.