FSC239Y5 Lecture Notes - Lecture 25: Phenolphthalein, Ejaculation, Laundry Detergent
Document Summary
Visual exam can be done solely with the overhead light. Stereomicroscope used to detect trickier surfaces like black leather. Detection of blood: presumptive chemical detection: methanol, phenolphthalein, hydrogen peroxide. Applied in this order (will change blood area to bright pink colour) Can be used on items that have been washed. Does not say what kind of body fluid. Paper (made with starch and dye) becomes blue when comes in contact with amylase. Amylase detected reaction may or may not indicate saliva. Stained red for sperm heads and green stained tails. Chemical constituents detected; may or may not indicate semen. After ejaculation, we are able to detect sperm in these cavities up to the following maximum times: Majority of semen lost from vagina within 2-3 days. 6 different body fluids simultaneously detected in a single test. Takes 5 minutes to prep sample, then results n 90 minutes.
