Alexander Badu-Boateng Analysis of Bodily fluids for Forensic purposes: From Laboratory testing to confirmatory identification at a Crime Scene Alexander Badu-Boateng BSc Biological Sciences

Introduction Forensic Science is the application of scientific analysis to law enforcement- Forensic Toxicology, Document examination, Forensic Entomology, etc Every Forensic process starts from the crime scene Branch of forensic science that deals with the identification and analysis of bodily fluids - Forensic Serology Serology precedes DNA Analysis in a Forensic Lab 22222222 Alexander Badu-Boateng

Brief History of Forensic Serology Around 1900, Karl Landsteiner discovered that there are four different types of human blood based on the presence or absence of specific antigens found on the surface of the red blood cells. This lead to the blood groups A,B,AB and O In 1940, Landsteiner and Weiner reported the discovery of the Rh factor by studying the blood of the Rhesus monkey Alexander Badu-Boateng

Objective To know how suspected bodily fluids are identified and analyzed in Forensic investigations Alexander Badu-Boateng

What are Bodily fluids Bodily fluids are liquids that originate from inside the body of humans Blood, Semen ,Saliva NB: Blood is the most common Biological stains in the dried state are reasonably stable and can be detected months or years after being deposited Alexander Badu-Boateng

Questions to answer when Bodily fluids are encountered Is the fluid or stain blood ,semen ,saliva ,etc? Is it of animal or human source? Can it be linked to a particular species or individual? Alexander Badu-Boateng

How to identify Bodily fluids (Crime Scene and Laboratory) Visual/Physical examination- Normally based on the experience of the Analyst. This isn't admissible in a court of law. It can only give a clue to the analyst Presumptive test: This test tells the presence or absence of a suspected fluid. Cannot confirm whether it’s from animal or human. Eg. Blood Confirmatory test: This test gives a high degree of specificity for the body fluid in question. Eg. Human blood Alexander Badu-Boateng

Alternate Light Source Use to visualize hidden stains in Clothing and other materials After detection of stains, presumptive tests can then be performed A dark room is needed Alexander Badu-Boateng

False Positive and False Negative results Some presumptive and confirmatory tests can react to the presence of other substances aside the suspected fluid to give a positive result- False positive Some presumptive and confirmatory tests can give a negative result as a result of the suspected fluid being insufficient for the test- False negative Reagent or kit failure can also give false positive or false negative results to serological tests. This problem can be avoided with testing the reagent or kit on a known bodily fluid (+ve Control) and a reagent blank (-ve control) Alexander Badu-Boateng

Presumptive Tests for Blood Benzidine Colour Test - Benzidine is carcinogenic so not used as often. Benzidine + Blood Stain + Hydrogen peroxide = pink color Kastle-Meyer Colour Test -Phenolphthalein + Bloodstain + Hydrogen peroxide = pink color Luminol Test - Reacts with blood to produce luminescence (glow) Hemastix: use to detect blood in urine but is now widely use to detect blood at the crime scene and in the lab. Reagent strips with TMB (Tetramethylbenzadine) ends.TMB changes from orange to green when it comes into contact with blood Alexander Badu-Boateng

Alexander Badu-Boateng

Presumptive test for Semen Acid Phosphatase Test: Acid phosphatase (AP) is an enzyme secreted by the Prostate gland into seminal fluid Several chemicals detect AP in semen- Alpha Naphthylphosphate: turns purple with semen Fast blue B Dye: turns purple with semen 4-methyl umbelliferyl phosphate: glows with semen contact 400 times AP in semen than any other bodily fluid NB: Reaction time of less than 30 secs. means you have found semen and not any other thing Alexander Badu-Boateng

Test for Saliva Amylase Test: Of the forensic laboratories that perform presumptive testing for saliva, the detection of amylase, an enzyme found at high levels in saliva, is currently the most widely utilized method Amylase is found in a variety of body fluids; saliva, blood, urine, sweat, tears, semen, breast milk, feces, and vaginal secretions , but is more concentrated in saliva Phabedas and Rapid Stain Identification of Human Saliva (RSID™-Saliva) Kits used by many crime labs for presumptive and confirmatory tests Alexander Badu-Boateng

Presumptive test for Urine Jaffe test: Creatinine can serve as a screening test for urine To a drop of stain extract on filter paper, add one drop of Picric acid followed by one drop of 5% Sodium hydroxide. Brown/orange color shows presence of Creatinine Alexander Badu-Boateng

Confirmatory tests for Blood Precipitin Test: Combining Human antiserum and human blood gives agglutination This principle has been employed in the production of many commerical kits Eg. Hexagon OBTI Kit Requires only small amount of blood Dried bloodstains as old as 10 - 15 years work Alexander Badu-Boateng

Confirmatory tests for Blood contd. Electrophoretic Method: Human antibodies and bloodstain are placed in wells on electrophoretic plate Electrical current is used to move antibodies and antigens towards each other If antibodies and antigens move towards each other and form a line of precipitation, it is human blood Alexander Badu-Boateng

Confirmatory test for Semen Prostate Specific Antigen (PSA or p30) Test: Prostate-specific antigen, or PSA, is a protein produced by cells of the prostate gland PSA is produced for the ejaculate, where it liquefies semen and allows sperm to swim freely PSA is present in small quantities in the serum of men with healthy prostates Alexander Badu-Boateng

Confirmatory test for Semen contd. When PSA is isolated and injected into rabbits, an immune response is triggered which produces antibodies for the PSA (anti-PSA) Serum is then collected from the rabbit Suspected human semen is placed in one well of an electrophoretic plate and anti-PSA is placed in the opposite well When an electric potential is applied, the antigens and antibodies move toward each other Formation of a visible line midway between the two wells shows the presence of human semen. Alexander Badu-Boateng

Alexander Badu-Boateng

Conclusion Identification and analysis of various bodily fluids is paramount in the investigation of many crimes Presumptive and confirmatory tests can be performed at the crime scene with the advent of simple-to-use commercial kits Alexander Badu-Boateng

References http://www.bluestar-forensic.com/ https://www.salimetrics.com/ https://en.wikipedia.org/wiki/Prostate- specific_antigen http://www.cancer.gov/types/prostate/psa- fact-sheet Alexander Badu-Boateng