Forensic Tests for Semen what you should know PDF

Preview

Summary

Notes highlighting the tests for suspects semen....

Description

Forensic Tests for Semen what you should know  

   



male ejaculate measures around 3.5 milliliters. Semen count may be affected by o Diet o Drug use o Age o Background Aspermia refers to another condition where the affected male produces no sperm Low sperm counts Vasectomized, oligospermic, and aspermiac males can still produce normal amounts of seminal fluid containing both prostate gland and seminal vesicle secretions which are detectable by forensic laboratory tests Confirmatory tests o Christmas Tree Test  most reliable confirmation for the presence of semen is the positive visual identification of sperm cells o RSID-Semen Strip Tests  Sensitive and specific for human semen  identifies the presence of the seminal vesicle-specific antigen, or semenogelin  no cross reactivity with other bodily fluids in males and females or with semen from other mammals  ID under poor conditions too Presumptive Tests o ALS  Dried semen stains are often off-white to faint yellow in color.  semen will fluorescence due to the presence of molecules such as Flavin and Choline-conjugated proteins  Woods lamp or crime scope o Blue to yellow depending o the light source  Issues  Exposure of the sample to factors such as heat, humidity, oxidizing agents, and microorganisms such as bacteria and mold can affect this fluorescent activity.  semen fluorescence can also be masked by certain types of fabrics and fabric treatments. o Acid Phosphatase Test  Prostate produeces a high amount of acid phosphatase into the semen  Brentamine Spot Test  In the presence of Alpha-Naphthyl acid phosphate and Brentamine Fast Blue, AP will produce a dark purple color in less than a minute  Non-semen AP enzyme reactivity is markedly slower when using the above mentioned spot test,  Not all AP enzymes in body fluids are not equal in their activity  May be discovered years later but moisture and heat will destroy AP  Analyses of post-coital vaginal swabs show that AP activity will markedly decrease after 24 hours and diminish after 48 hours o PSA  P30 molecule  ABAcard or P30 Test  PSA produced in high amiunts in the male prostate gland  Issues

o o

his antigen can also be found in very small amounts in fecal material and sweat. can also exist in female urine and breast milk...