Download Notes - Intro to Serology

Why Use Blood?
Blood Type = Class Evidence
– Narrows the pool of suspects to a group
White Blood Cells (DNA) = Individual Evidence
– Narrows the pool of suspects to an individual
Droplets = Location of Crime, Movement of Victim,
Types of Weapon
Spatter = What Happened at the Scene
History Lesson
1900: Kastle develped 1st presumptive blood test
1901: Karl Landsteiner classified blood into types A, B, and O
1902: Alfred on Descastello discovered blood type AB
1937: Rh factor determined
1959: Dr. Mark Perutz described structure of hemoglobin
1971: Dr. Blumberg developed method of antibody detection
1982: Dr. Alec Jeffreys used WBCs to produce 1st DNA profile
Composition of Blood
Erythrocytes: (RBCs) contain
hemoglobin which carries oxygen
Leukocytes: (WBCs) destroy
infectious agents
Plasma: yellowish liquid portion of
blood containing electrolytes,
nutrients, vitamins, hormones,
clotting factors, and antibodies
Thrombocytes: (platelets) clot
together during coagulation to
seal wounds and prevent blood
loss
Human Blood Types
15 systems identified but ABO & Rh are the most important
Determined by the presence/absence of antigens on the
surface of the cells which is influence by genes
Genetics Break
Chromosome: threadlike structure in the
cell nucleus
Gene: basic unit of heredity, consisting of a
DNA segment located on a chromosome
Locus: physical location of a gene on a
chromosome
Allele: any of several alternative forms
of a gene located at the same point on
a particular pair of chromosomes
Genetics Break
Genotype: particular combination of genes present in the cells
of an individual
Homozygous: having two identical allelic genes on two
corresponding positions of a pair of chromosomes
Heterozygous: having two different allelic genes on two
corresponding positions of a pair of chromosomes
Phenotype: physical manifestation of a genetic trait such as
shape, color or blood type
Punnett Practice
Gary has Type O Blood and Patty has Type AB Blood.
Determine the probable outcomes of their children.
Gary's genotype
ii
Patty's genotype
IAIB
Children genotype
50% IAi : 50% IBi
i
i
IA
IAi
IAi
IB
IBi
IBi
Children phenotype
50% Type A : 50% Type B
Human Blood Types
% U.S.
Population
42%
12%
3%
43%
Antigen: substance (protein) that stimulates the body to
produce antibodies against
Antibody: protein in blood that destroys/inactivates a specific
antigen
**85% = Rh positive**
Serology…
…study of antigen-antibody
reactions
Antibodies have two reactive
sites (bivalent) which allows
them to bind to two cells at once
Agglutination: clumping
together of RBCs by the action
of an antibody
**Antibody reaction test is used to identify blood type**
Blood Typing Tests
Test for presence of A, B,
and Rh proteins
3 separate tests are
performed – 1 for each
protein
If agglutination occurs then
the test is positive
Human vs. Animal