Green+C+R100-105

Ramsland pages 100-105

Revealing Fluids
 * The analysis of the properties and effects of serums--blood, semen, saliva, sweat, and even fecal matter--is called serology.
 * There are many types of enzyme tests for bodily fluids.
 * Polymarker typing analysis, HLA-DQA1- DNA test for samples of limited quality
 * Biological evidence at a crime scene may be fresh liquid, coagulated, dried, pr in the form of spatters, a small drop, or a stain.
 * Each form dictates a different method of preservation and collection.
 * Blood is unaffected by temperature, humidity, or atmospheric pressure. It remains uniform.
 * Dr. Leon Lattes restored dried blood with saline solutions so it could be tested for antigens. Blood typing involves many different enzymes and proteins.
 * A positive test from a presumptive test can lead to other tests to confirm.
 * Luminol testing- reacts to the hemoglobin in blood giving off an luminescence; can destroy some properties of blood; also reacts with bleach and some metals
 * Flourescein reagent- illuminated with UV light; persists longer the luminol; better for getting photographs
 * Kastle-Meyer Color Test- cotton swab is rubbed through the area suspected to be blood, a drop of phenolphthalein applied and then a drop of hydrogen peroxide; if blood is present the swab will turn pink or red; also reacts to potatoes and horseradish
 * Leucomalchite- turns green in the presence of blood
 * Ortho-tolidine- turns an intense blue at the presence of blood
 * Hermastrix strip- turns green in the presence of blood
 * Precipitin tests are used to determine if blood is human or aminal.
 * In a forensic test for human blood, a sample of the questioned blood is put in a test tube over the serum
 * In a gel diffusion test, the questioned blood is placed on the glass slide of gel next to the anithuman serum, the slide is stimulated with electric current, a line forms where they meet--called a precipitin line-- that means the sample is human blood
 * lectrophoresis