CHE E122 Lecture Notes - Lecture 6: Cyanoacrylate, Squalene, Sebaceous Gland
Document Summary
Every human being carries a unique fingerprint - therefore, it is possible to determine whose fingerprint it is. There are seven types of fingerprint patterns. When you touch something, you leave oils where you touched - known as sebaceous fluids. Sebaceous fluids include squalene, stearic acid, oleic acid, lactic acid and amino acid. Superglue fuming is a technique to reveal and "fix" latent fingerprints on non-porous items such as bottles, firearms and knives (metals, plastics etc). Starts with heating liquid methyl-2-cyanoacrylate which releases vapours that adhere only to the oily residue of a fingerprint. If necessary, fluorescent markers can be used to improve contrast (makes it easier to see). Cyanoacrylate monomer contacts the fingerprint residue and white polymer grow only along the fingerprint ridge details. I2 fuming is another technique used to reveal fingerprints. Good for sebaceous deposits on porous and non-porous materials. Non-destructive so it can be used with other techniques. Takes some time for the image to appear.
