Forensic Science K. Davis

1. Blood Basics Forensic Science K. Davis Some material retrieved from T. Trimpe http://sciencespot.net/

2. General Information • Blood is the most common & usually the most useful bodily fluid left at a crime scene. • 1901 – Karl Landsteiner – discovered method to type blood; won Nobel Prize • 1937 – Rh factor was discovered • Composed of a mixture of cells, enzymes, proteins, and inorganic substances

3. What makes up our blood? • Red Blood Cells(Erythrocytes) – The most abundant cells in our blood; they are produced in the bone marrow and contain a protein called hemoglobin that carries oxygen to our cells. • White Blood Cells(Leukocytes)– They are part of the immune system and destroy infectious agents called pathogens.

4. What makes up our blood?(cont.) • Plasma – This is the yellowish liquid portion of blood that contains electrolytes, nutrients and vitamins, hormones, clotting factors, and proteins such as antibodies to fight infection. It comprises 55% of the blood content. • Platelets(Thrombocytes) – The clotting factors that are carried in the plasma; they clot together in a process called coagulation to seal a wound and prevent a loss of blood.

5. Agglutination (Blood Clotting) • Blood clots when protein (fibrin) traps and enmeshes RBCs. • If you remove the clotted material, you will have serum left.

6. Blood Facts • The average adult has about FIVE liters of blood inside of their body, which makes up 7-8% of their body weight. • Blood is living tissue that carries oxygen and nutrients to all parts of the body, and carries carbon dioxide and other waste products back to the lungs, kidneys and liver for disposal. It also fights against infection and helps heal wounds, so we can stay healthy. • There are about one billion red blood cells in two to three drops of blood. For every 600 red blood cells, there are about 40 platelets and one white cell. http://www.bloodbankofalaska.org/about_blood/index.html

7. Genetics of Blood Types • Your blood type is established before you are BORN, by specific GENES inherited from your parents. • You inherit one gene from your MOTHER and one from your FATHER. • These genes determine your blood type by causing proteins called AGGLUTINOGENS to exist on the surface of all of your red blood cells.

8. There are 3 alleles or genes for blood type: A, B, & O. • Since we have 2 genes, there are 6 possible combinations. • Antigens (On RBC Surface) • -more than 15 systems identified • - ABO and Rh most important • - Type A : has A antigens -Type B : has B antigens • - Type AB : has both -Type O : has neither • - Rh: Positive (has D antigen) or Negative (does not) Blood Types AA or AO = Type ABB or BO = Type BOO = Type OAB = Type AB What are blood types?

9. http://learn.genetics.utah.edu/units/basics/blood/types.cfm Blood Typing Methods - serum/plasma contains proteins (antibodies) that destroy specific antigen - If you add Anti-A serum to Type A blood, you get agglutination (clotting).

11. How common is your blood type? 46.1% 38.8% 11.1% 3.9% Frequency of basic blood types: O: 43%, A: 42%, B: 12%, AB: 3%; Rh: positive – 85%, negative – 15%

12. Blood Transfusions O A B AB A blood transfusion is a procedure in which blood is given to a patient through an intravenous (IV) line in one of the blood vessels. Blood transfusions are done to replace blood lost during surgery or a serious injury. A transfusion also may be done if a person’s body can't make blood properly because of an illness. Universal Donor • Who can give you blood? • People with TYPE O blood are called Universal Donors, because they can give blood to any blood type. • People with TYPE AB blood are called Universal Recipients, because they can receive any blood type. • Rh +  Can receive + or - • Rh -  Can only receive - Universal Recipient

13. Rh Factors • Scientists sometimes study Rhesusmonkeys to learn more about the human anatomy because there are certain similarities between the two species. • While studying Rhesus monkeys, a certain blood protein was discovered. This protein is also present in the blood of some people. Other people, however, do not have the protein. • The presence of the protein, or lack of it, is referred to as the Rh (for Rhesus) factor. • If your blood does contain the protein, your blood is said to be Rh positive (Rh+). • If your blood does not contain the protein, your blood is said to be Rh negative (Rh-). A+ A-B+ B-AB+ AB-O+ O- http://www.fi.edu/biosci/blood/rh.html

14. Blood Evidence • Blood samples – Can be analyzed to determine blood type and DNA, which can be matched to possible suspects. • Blood droplets – Can be analyzed to give clues to the location of a crime, movement of a victim, and type of weapon. • Blood spatter – Can be analyzed to determine patterns that give investigators clues to how a crime mighthave happened.

15. Fish Blood Bird Blood Horse Blood Cat Blood Frog Blood Human Blood Snake Blood Dog Blood MicroscopicViews

16. Forensic Characterization Of Blood - Questions to ask 1. Is it blood? 2. What species? 3. If human, how closely can it be associated to a particular individual?

17. 1) Is it blood? - must have enough blood - must be in good condition for testing - some chemicals damage blood to the point that DNA typing then cannot be performed - putrefaction can also degrade samples - dried samples may not have decayed as much https://forensicbiology.dna.gov/embed_flv?link=https://static.dna.gov/flash/videos.swf&flvLink=https://static.dna.gov/flash/pdi_s02_m02_02_a.flv&slides=0

18. Tests - Presumptive Tests: indicate a likelihood that blood is present, but don’t establish it as fact 1. Benzidine Color Test – turns pink 2. Kastle-meyer Color Test – turns pink - Both Kastle-Meyer and Benzidine are based on the observation that blood hemoglobin possesses perioxidase-like activity

19. Tests cont. 3. Hemastix: useful in field;turns green 4. Luminal: results in production of light 5. Very sensitive 6. Doesn’t interfere with DNA

20. Tests cont. - Confirmatory tests: are certain about blood presence - More expensive and time consuming - Also called Microcrystalline tests (characteristic crystals form when chemicals are added) - Teichmann and Takayama tests

21. 2) What Species? - Precipitin Test - Precipitin = an antibody that reacts with its corresponding antigen to form a precipitate - If you inject an animal with human blood, antibodies form that react with human blood to neutralize it. - Isolate these antibodies = human anti-serum https://static.dna.gov/flash/pdi_s02_m02_01_b.2.swf

24. Various Methods to Perform Tests Gel diffusion: extracted bloodstain and human anti-serum are placed in gel; if human, line will form

25. Various Methods to Perform Tests Electrophoresis : uses current - Very sensitive - Requires small amount of blood - Can use old, dried blood - Can use blood diluted by washing in saline

26. 3) Can blood be associated to a particular individual? - ABO Types (whole blood) • Typing Dried Stains: absorption, elution https://static.dna.gov/flash/pdi_s02_m02_03_a.2.swf - No RBCs present because they have degraded, but you can still get the antigens out. - Treatment with anti-serum; antibody binds to its specific antigen - Excess antibodies are removed by washing

27. Typing Dried Stains: absorption, elution (cont.) - Antibodies and antigens are eluted or freed from one another by heating the stained material - Add known RBCs & agglutination occurs, if antigens present on the added blood cells were originally on stained material as well - sensitive test - 11 year old blood stains have been successfully typed

28. Blood Enzymes & Proteins - different forms used to discriminate among bloodstains -Enzyme: type of protein that acts as a catalyst for certain specific reactions - Many are polymorphic and can be separated into iso-enzymes (multiple molecular forms of an enzyme, each having same or similar enzyme activities)

30. Principles of Heredity - Transmission of our Traits - all antigens, polymorphic enzymes, and proteins are genetically controlled traits - transmission of hereditary material is through our genes which are positioned on our chromosomes - alternative forms of genes are called alleles

31. Principles of Heredity cont. • Reproductive cells (egg and sperm) contain half of the chromosomes/genes of the parent. • - During fertilization, the new zygote receives one half of its chromosomes/genes from the mother and one half from the father.

32. Principles of Heredity cont. - homozygous: the two genes are alike - heterozygous: the two genes are different - genotype: the genes present in an individual (https://static.dna.gov/flash/DNACD_mod02-1-13.swf ) • phenotype: the physical manifestation of the genetic trait Genotype -BB, Bb, & Bb = phenotype brown -bb = phenotype blue

33. Principles of Heredity cont. - The principles of heredity is useful in determining ABO blood types in children and parents. - Punnet Squares can be used to determine blood type

34. Example Male parent is Type O (phenotype) and therefore has OO as his genotype. Female parent is Type AB (phenotype) and therefore has AB as her genotype. Construct a Punnet Square to determine possible genotypes and phenotypes of their offspring. A B O O

35. Answer 50% = Type A (AO); 50% = Type B (BO) Bottom line: no blood group gene can appear in a child unless it is present in at least one of the parents. - Useful in paternity testing. A B O AO BO O AO BO

36. Other Bodily Fluids Semen: - normal male releases 2.5 to 6 ml of seminal fluid during ejaculation - each ml contains 100 million or more sperm

37. Forensic Characterization of Semen 2 step process: - Stain must be located - Sometimes is clearly visible - Other times difficult to find • can use test to determine presence of seminal fluid - Sperm must be identified

38. Presumptive Tests for Semen Acid Phosphatase Color Test: - Acid phosphatase = enzyme produced by seminal vesicles - use of reagent on materials results in fluorescent areas under UV light in presence of semen - May produce a false positive

39. Confirmatory Tests for Semen Microscopic Examination: - examination for intact sperm or sperm head - If individual had vasectomy, there may be no sperm present.

40. Confirmatory Tests for Semen cont. Prostate-specific antigen (PSA): - Present even in individuals who have had a vasectomy - Is an antigen-antibody reaction

42. Secretors - an individual who secretes his or her blood-type antigen(s) in body fluids (semen, saliva, etc) • 80% of individuals • Can determine blood types from semen in 80-85% of individuals

43. Saliva - may be recovered from everything from stamps to food to bite marks - may reveal ABO antigens and blood types in secretors and sometimes can yield enough DNA for profiling - Testing for saliva involves testing for alpha-amylase enzyme found in saliva – is only a presumptive test - No confirmatory tests for saliva

44. Blood Additional Links • https://static.dna.gov/flash/DNACD_mod02-1-12.swf • https://propcrimes.dna.gov/embed_flv?link=https://static.dna.gov/flash/videos.swf&flvLink=https://static.dna.gov/flash/PropCrimesVideos/pro_m03_t14.flv&slides=0 • https://propcrimes.dna.gov/embed_flv?link=https://static.dna.gov/flash/videos.swf&flvLink=https://static.dna.gov/flash/PropCrimesVideos/dna-2-34.flv&slides=0 • https://propcrimes.dna.gov/embed_flv?link=https://static.dna.gov/flash/videos.swf&flvLink=https://static.dna.gov/flash/PropCrimesVideos/dna-2-31.flv&slides=0 • https://propcrimes.dna.gov/embed_flv?link=https://static.dna.gov/flash/videos.swf&flvLink=https://static.dna.gov/flash/PropCrimesVideos/dna-2-29.flv&slides=0 • https://propcrimes.dna.gov/embed_flv?link=https://static.dna.gov/flash/videos.swf&flvLink=https://static.dna.gov/flash/PropCrimesVideos/pro_m03_t06.flv&slides=0 • https://propcrimes.dna.gov/embed_flv?link=https://static.dna.gov/flash/videos.swf&flvLink=https://static.dna.gov/flash/PropCrimesVideos/dna-2-28.flv&slides=0