Transcript BLOOD - Somers Public Schools

BLOOD
. Blood- A mixture of cells, enzymes,
proteins, and inorganic substances.

Plasma- The fluid part of blood
 Formed Elements- The cells
 Platelets- Aid in clotting process
At a crime scene, ask three basic “blood”
questions:
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Is this blood?
How to tell: Chemical analysis with KM reagent
or Luminal
From
what species did the
blood originate?
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How to tell: DNA and/or protein analysis
If
the blood is human, whose is
it?

How to tell: DNA and/or protein analysis
Blood Typing (Serology)
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Blood Typing (Serology)
The three alleles for blood are: A, B and O
 These alleles can combine either…
 a.) homozygous- two of the same genes
 b.) heterozygous- two different genes
The basic blood types(phenotypes) and their gene
combinations(genotype)
A-type= IAIA (homo.) or IA i (hetero.)
42%
B-type= IBIB(homo.) or IBi (hetero.)
12%c.
O-type= ii(homo.)
43%
AB-type= IAIB(hetero.)
3%
Blood Tests
Agglutination: clumping, used to detect
blood type
 Immunological assay: Detect drugs by
using serum reaction to a drug protein
complex
 Kastle –Meyer: Detects blood by examining
the peroxidase-like activity of hemoglobin in
blood to catalyze the oxidation of
phenolphthalein (a pH test)
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Blood Tests cont..
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Precipitation test- To detect human or
animal blood. Animals are injected with
human blood (usually rabbits), antibodies
are formed that react with the invading
human blood to neutralize its presence.
The serum will contain human antiserum.
Then gel diffusion is used to detect the
species of blood.
Blood Type is Hereditary
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Everyone receives their genes in pairs.
So, one blood type gene/letter comes from
each parent
Antibodies
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Antibodies can be used to determine blood typing.
Anti-bodies are an organism’s self-defense mechanism and
react to specific antigens.
There are a 15 common blood antigens which can be tested.
RH Factor is often association with blood typing and is
referred to as positive(+) or negative (-) antigen test.