Serology-study of biological fluids involving specific antigen and serum antibody reactions

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1 Forensic Serology

2 Serology-study of biological fluids involving specific antigen and serum antibody reactions 1901-Karl Landsteiner-ABO blood type system Blood types based on presence of agglutinogens (agglutinating antigens) on surface of red blood cells (erythrocytes)

3 Antigens Proteins that stimulate production of antibodies On surface of erythrocytes Types- A and B Antibodies-produced against antigens not present Ex. Type A blood has A antigens, but B antibodies

5 Blood Types Blood Type Antigen Antibodies in plasma Can give to Can receive from A A Anti B A,AB O, A B B Anti A B,AB O.B AB AB No A or B AB O,A,B,AB O Neither A nor B A and B O,A,B,A B O

6 Frequency of Blood Types

7 Blood Factors If mixed-blood agglutinates (solidifies) -death Rh factor (antigen D) More than 100 blood factors

8 Blood 1. Cells- Red blood cells (Erythrocytes) Platelets (Thrombocytes) White blood cells (Leukocytes) 2. Enzymes 3. Proteins 4. Fluid 5. Inorganic substances (gases)

9 Blood Plasma Liquid part of blood Serum (liquid that separates from blood) and proteins in water 55% of blood volume Fibrin-blood clotting protein

10 Erythrocytes Red blood cells Transport oxygen and carbon dioxide Has hemoglobin-blood protein carries oxygen in blood Most numerous blood cells

11 Leukocytes (White Blood Cells) Monocytes Lymphocytes Neutrophils Part of Immune System Fight infections

12 Platelets Thrombocytes Involved in blood clotting

13 Antiserum Serum that contains antibodies (proteins that destroy specific antigens ;immunoglobins) Used in determining blood types If antiserum causes agglutination, then the blood type can be determined

14 Bloodstain Characteristics As blood dries-harder to type Erythrocytes lyse, or break open, upon drying No cells in dried bloodstain-antigens will be present

15 Guideline for Examining Blood Determine if it is blood Determine species If human blood-determine if it can be individualized Blood is class evidence

16 Forensic Characterizations of Bloodstains 1. Is it blood? 2. From what species did the blood originate? 3. If the blood is human, how closely can it be matched to one individual?

17 Is it Blood? Kastle-Meyer Color Test Phenolphthalein Hemoglobin-peroxidase-like activity Peroxidases-speed up oxidation of compounds by peroxides Blood, phenolphthalein, and hydrogen peroxide-hemoglobin is deep pink

1.) Hydrogen peroxide 2.) Heme has peroxidase-like activity-breaks up peroxides.h2o2 decomposed to H2O and oxygen 3.) Oxygen combine with the KM, phenolphthalein color-indicator 4.

18 1.) Hydrogen peroxide 2.) Heme has peroxidase-like activity-breaks up peroxides.h2o2 decomposed to H2O and oxygen 3.) Oxygen combine with the KM, phenolphthalein color-indicator 4.) When KM solution is prepared-boiled remove oxygen- When it turns colorless-shows KM had most of its oxygen removed and is now "oxygen hungry". So... now we have the makings of a kind of love story: the KM wants oxygen, and there's a lonely oxygen radical floating around, un-spoken for 5.) Pink color: occurs when oxygen radical "hooks up" with KM reagent-oxidation of KM and causes it to turn pink.

19 Luminol Test Chemiluminescence of luminol The most sensitive chemical test that is capable of presumptively detecting bloodstains diluted up to 300,000 times

21 Luminol (C8H7O3N3) mixed with hydrogen peroxide and hydroxide If hemoglobin and luminol interact-iron in hemoglobin catalyzes rxn b/w H2O2 and luminol Redox rxn-luminol loses N and H and gains O-produce 3-aminophthalate 3-aminophthalate in energized state e-s in oxygen are boosted to higher orbitals-e-s then fall back to lower energy level-emit extra energy as light photons rent=luminol.htm&url= Echm_tgc/JPPdir/JPP1999/

Immunoassay Techniques Presumptive test for detection of drugs in blood and urine Antibodies reacting with drugs don t occur naturally Produced in animals by combining drug with a protein and

23 Immunoassay Techniques Presumptive test for detection of drugs in blood and urine Antibodies reacting with drugs don t occur naturally Produced in animals by combining drug with a protein and injecting into animal Drug-protein complex acts as antigen stimulating animal to produce antibodies The recovered blood serum of animal contains specific antibodies to the drug-this is human antiserum

EMIT- Enzyme Multiplied Immunoassay Technique-drug screening in urine and blood-add antibodies to blood or urine, then add chemically labeled drug- will compete with drugs in urine or blood (if

24 EMIT- Enzyme Multiplied Immunoassay Technique-drug screening in urine and blood-add antibodies to blood or urine, then add chemically labeled drug- will compete with drugs in urine or blood (if present) for antibody binding sites. The number of remaining unbound labeled drug-proportional to drug s concentration in urine. ex. Methadone-add methadone antibodies and chemically-labeled methadone to urineex. THC tetrahydrocannabinol- metabolite-thc-9-carboxylic acidantibodies are prepared against this metabolite-one-millionth of a gram-can detect up to 10 days after use

25 Steps required to produce monoclonal antibodies

26 Polyclonal vs. Monoclonal Antibodies Polyclonal antibodies-series of antibodies which can attack some site on antigen-vary in specificity and binding abilities Monoclonal antibodies-identical antibodies that interact with one site on an antigen

27 Monoclonal antibodies Immunoassay tests for abused drugs made with monoclonal antibodies

28 Precipitin Test Test to determine species of blood Precipitin-an antibody that reats with its corresponding antigen to form a precipitate Animal blood injected with human bloodantibodies form that react with human blood to neutralize its presence Antibodies can be recovered in serum Serum is human anti-serum

30 Precipitin tests Blood is placed on antiserum in tube Blood will react with anitbodies in antiserum Leaves precipitin band

31 Gel Diffusion

32 Blood Enzymes and Proteins Enzymes-proteins that regulate chemical reactions Polymorphic enzymes-enzymes of many forms Ex. PGM-Phosphoglucomutase-ten types of PGM

33 Secretors 80 % of individuals are secretors Secretors-antigens in most body fluids (saliva, semen) and blood

34 Bloodstains and Probability Antigens, enzymes, and proteins occur independently Probability-product of their distributions-rule of Multiplication Ex. If bloodstain is type A, it originated from 42% of population. If it has PGM 1-origin narrowed to 24% 42% X 58%

35 Study performed by Herbert MacDonell: 1. Surface texture- harder and less porous surface-less spatter 2. When blood drop hits hard surface-breaks up on impact-casting off smaller droplets 3. Impact angle of blood-inverse Sin W/L W=width of stain L=length of stain

36 Area of convergence on a two-dimensional plane. Convergence represents the area from which the stains emanated.

38 g/links/animations/ images/blood%20s patters.swf

43 Categories of Bloodstains PASSIVE TRANSFER PROJECTED

45 By measuring the length and width of a bloodstain, the impact angle can be calculated SIN < = Width (a) 1.5cm Length (c) 3.0cm Width (a) 1.5cm = SIN < Length (c) 3.0cm 0.5 = SIN < < = 30 degrees

47 Collection of Wet Blood Collected and refrigerated Insufficient amount-air-dry No plastic containers Each stained article-packaged in paper bag or cardboard box

48 Drying Cabinets in Crime Lab

49 Collection of Dried Bloodstains Stained sample packaged Sample of unstained surface removedsubstrate control to confirm test results from stain and not substrate on which it was deposited Absorb blood onto damp swab

50 Blood Collection Bloodstains compared to blood specimens from victims and suspects Collect 5cc from individuals-add anticoagulant EDTA (ethylenediamine tetraacetic acid)- inhibits enzymes from degrading DNA

51 Heredity of Blood Types Genes-basic unit of heredity-located in DNA Chromosomes-structures made of DNA Humans-46 chromosomes in somatic cells 23 chromosomes in gametes Zygote-fertilized egg Alleles-forms of genes

52 Multiple Alleles of Blood Types Homozygous-gene pair made of two similar genes-ex. AA and OO Heterozygous-gene pair made up of two different genes-ao A and B-dominant genes O-recessive gene AB-codominant

53 Genotype and Phenotype Genotype-pair of alleles-no laboratory test to determine genotype ex. AA or AO Phenotype-physical characteristic-ex. Type A blood Punnett Squares used to determine genotypes Used in Paternity Testing o Father o Mother A B

54 Forensic Characterization of Semen Each Male Ejaculate ml of seminal fluid Each ml-100 million or more spermatozoa Acid-Phosphatase Color Test-enzyme secreted by prostate gland Oligospermia-low sperm count Aspermia-no spermatozoa in seminal fluid

55 If semen is detected, but contains no spermatozoa, how do you prove presence of semen? Protein called p30-unique to seminal plasma

Serology. Antigen-Antibody Reaction. Antigen-Antibody Reaction. Chapter 8b: Forensic Serology

Serology. Antigen-Antibody Reaction. Antigen-Antibody Reaction. Chapter 8b: Forensic Serology Serology Chapter 8b: Forensic Serology Antigen-Antibody Reaction When an animal is injected with an antigen its body will produce a series of different antibodies. Antigen-Antibody Reaction This collection