id & characterization of blood & bloodstain. before dna there was: serology
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ID & Characterization of Blood & Bloodstain
BEFORE DNA THERE WAS:
SEROLOGY
Serologyexamination & analysis of body fluids
SerologySTAINS often deteriorated and degraded
SerologyCorrect steps must always be followed - PROTOCOL
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
Presumptive testingNegative result questioned stain is not likely blood
Positive result questioned stain is likely blood
Presumptive Screening Tests
Presumptive tests produce a color reaction or release of light
Tests rely on hemoglobin presence
Catalytic Color TestSample a stain with a clean, moist
cotton swabAdd a drop of reagentAdd a drop of hydrogen peroxideColor will develop immediately
Catalytic Color TestExamples:
Benzidine Alder – blue-dark blue
Phenolphtalein-Kastle-Mayer Test – pink
O-Tolidine test – blueLeucomalchite Green (LNG) – green
Tetramethylbenzidine- Hemastix – green –blue green
CHEMILUMINESCENCE
light is emitted as a product of the chemical reaction
FLUORESCENCE
light is emitted when a substance is exposed to a shorter wavelength of light
Chemiluminescence & FluorescenceMore sensitive than color tests
May damage blood stain (no blood/DNA typing)
Used to locate and define areas of blood old blood stains cleaned floor
LUMINOL
Method similar to color test combined with oxidant and sprayed over area thought to contain blood
Emits a blue-white to yellow green glow
Extremely sensitive – 8 paint layers
FLUORESCEIN• combined with oxidant and sprayed over area thought to contain blood
• Fluoresces when treated with a UV light• includes a thickener• makes it more effective on vertical surfaces• Study showed no interference with DNA analysis
Confirmatory test for BloodConfirms presence of bloodSeveral test use crystal formation to detect hemoglobin
2 types of testsTeichmann testTakayama test
SPECIES ORIGIN
Most methods test for serum proteins
Serum proteins are found in all animals, but are slightly different
Species ID methods based on antigen/antibody interactions
Microscopic Views
Bird Blood
Cat Blood
Dog Blood
Fish Blood
Frog Blood
Snake BloodHuman Blood
Horse Blood
GENETIC MARKERS IN BLOOD
If a stain is blood, and it is human blood, then whose is it?
Blood Group MarkersProtein/Enzyme MarkersDNA
Blood Group Markers
ABO MarkersLewis SystemRhesus System
Many blood group markers, including:
Genetic Markers in BloodYour blood group is genetically controlled and a lifelong characteristic
Types of markersAntigen MarkerProtein MarkerEnzyme Marker
BLOOD GROUP MARKERS
ABO MARKERS
Look at antigens on Red Blood Cells
antigens are glycoproteins are attached to outside of cell
Introduction to Blood
ABO blood groups found on outside of cell
Blood Group Markers
ABO Markers (antigen and antibodies)
person will have antibodies (A or B) to whatever blood group he/she doesn’t have
Otherwise, a persons blood would clump up and cause death
Blood Group MarkersABO Markers (antigen and antibodies)
Blood Type Antigen(blood group)
Antibody % population
A
B
AB
O
Blood Group MarkersABO Markers (antigen and antibodies)
Blood Type Antigen(blood group)
Antibody % population
A A Anti-B 40
B
AB
O
Blood Group MarkersABO Markers (antigen and antibodies)
Blood Type Antigen(blood group)
Antibody % population
A A Anti-B 40
B B Anti-A 10
AB
O
Blood Group MarkersABO Markers (antigen and antibodies)
Blood Type Antigen(blood group)
Antibody % population
A A Anti-B 40
B B Anti-A 10
AB A & B none 5
O
Blood Group MarkersABO Markers (antigen and antibodies)
Blood Type Antigen(blood group)
Antibody % population
A A Anti-B 40
B B Anti-A 10
AB A & B none 5
O H Anti-A & Anti-B
45
BLOOD GROUP MARKERS
ABO MARKERS
Testing is similar to species test
An anti-A, anti-B, or anti-AB antiserum (containing antibodies) is reacted with blood stain to detect blood cells
A, B, or AB blood cells are reacted with blood stain to detect antibodies
BLOOD GROUP MARKERS
ABO MARKERS
Tests can get complicated with absorbing and releasing cells
Final step is usually testing for agglutination (blood clumping)
BLOOD GROUP MARKERS
ABO MARKERS
A cells clump with anti-A B cells clump with anti-B AB cells clump with both O cells do not clump
How common is your blood type?
Rh FactorsScientists sometimes study Rhesus monkeys
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
Blood TransfusionsA 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.
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 Donor
Universal Recipient
