Chapter 9 Identification of Saliva and Misc Biological

Chapter 9: Identification of Saliva and Misc. Biological Fluids Forensic Biology by Richard Li

Biological Characteristics Human salivary glands produce 1. 0 -1. 5 liters per day Mostly water Amylase- digests carbohydrates in the oral cavity Identification of amylase indicates saliva Enzymes that cleave polysaccarides that are composed of D-glucose units connected by (α 1 -4) linkages ▪ Starch Forensic Biology by Richard Li 2

Biological Characteristics Starch Amylose Amylopectin Two types of amylases: β-amylase ▪ Plant and bacterial sources α-amylase ▪ Human salivary (HSA) ▪ Human pancreatic (HPA) Forensic Biology by Richard Li 3

Presumptive Assays Visual Examination ALS (470 nm), Microscopic Starch-iodine assays Iodine used to test for starch Not specific Colorimetric assays Dye-labeled amylase substrates are employed Phadebas test Forensic Biology by Richard Li 4

Confirmatory Assays Immunochromatographic Assays RSID-Saliva ELISA Monoclonal HSA antibody RNA-based assays Certain genes are specifically expressed in certain types of cells Forensic Biology by Richard Li 5

Misc. Biological Fluids Vaginal secretions, Menstrual blood, Urine, Feces, Vomitus Less frequently encountered Can be probative in certain cases Forensic Biology by Richard Li 6