Forensic Serology

Using Blood in Forensics Test for Provides Analyze bloodstains

Livor mortis-

Karl Landsteiner In 1901 he discovered that all humans

He discovered This saved millions of lives by

Other researchers were able to discover the Rh factor because of his research

29 years later, they gave Karl a Nobel Prize

SerologySerology is the __________________________________________________. A forensic serologist may analyze a

variety of body fluids including saliva, semen, urine, and blood. From 1950 to the late 1980’s, forensic serology was a most important part of lab procedures. With the development of DNA techniques, more time, money, and significance was placed in developing DNA labs. However, with limited funds and the time required for DNA testing, most labs still use many of the basic serology testing procedures.

Blood and Forensics So forensic scientists used this tool to link blood from a crime scene to an individual

Role of blood in the human body1. Blood is …2. Transportation

3. Regulation

4. Protection

What is Blood? ____________________________________________:

Platelets ( ) Plasma

Characteristics of Red Blood Cells Red blood cells (_____________________) are Red blood cells In addition to There are at least Role of RBCs Transport

– O2 + hemoglobin = bright red blood Remove

– CO2 + hemoglobin = dark red blood RBCs are destroyed after about 120 days

Summary of Functions of WBCs Leukocytes . Eosinophils Basophils

Lymphocytes

Blood Platelets Blood platelets are . Thrombopenia, Thrombocytosis

Blood Clotting The blood clots when … SERUM

Blood Clotting and Forensics The clotting process begins

– 1st – 2nd

–

How long ago did the victim begin bleeding? – A few minutes: – Less than an hour:– .– Several hours:

Hematocrit A blood hematocrit is

Blood Plasma Plasma is Plasma is mostly water, with a mixture of…

Buffy Coat?

ABO Blood Group Antigens are on … Adverse transfusion reactions are avoided by …

– Adverse reactions are due to …Blood Groups and Transfusions Antigens and Antibodies

Agglutination is

Rh Blood Group The Rh factor If the Rh factor surface protein is present, There are no corresponding antibodies in the plasma unless a person with Rh-negative blood is transfused with.

Blood GroupsType Anitgen Antigen Can receive from Can donate toA A B A, O A, ABB B A B, O B, ABAB A and B NONE A, B, O ABO NONE A and B O A, B, O

Population Distribution of Blood Types in the U.S. :

Genotype: Phenotype:

Genetic Blood Typing (Genotypes) Mother

Father

A B OABO

Transmission of our traitsAllele Combinations Blood Type

(phenotype)AA + AOBB +BO

ABOO

Paternity Testing .If a man and child share the HLA markers, …The Haptoglobin marker +

DRUG - DETECTIONHypothesis: Since foreign substances in blood are identified and then isolated by the immune system, it should be able to detect the presence of drugs and other chemicals.This hypothesis is _______________. The immune system only...

We can fool the immune system The drug can be This drug-protein combo can be The animal’s immune system will

We can isolate And use these antibodies to

Now how does a criminalist use these antibodies? To detect drug presence in blood, urine, etc. A.K.A. EMIT stands for EMIT is most often used One of the primary THC metabolites is

Questions for a Criminalist:Is it blood? Is it human blood? If it is human, can it be linked to a suspect / victim and how closely?

The Kastle-Meyer Test to ID Blood (tests for hemoglobin) Phenolphthalein = colorless Blood+ phenolphthalein + Certain vegetable matter can

Death By Potato? Although the Kastle-Meyer test can give a false positive in the presence of certain plant matter, it is unlikely that

this plant matter would be present at a crime scene and be mistaken for blood.Other blood detection tests

Doctors use Moisten them with distilled water and

(Bayer Hemastix©)Luminol

Luminol is a chemical that exhibits _______________________________________________ when mixed with an appropriate oxidizing agent. It is a ________________________________________________________ most polar organic solvents.

Usually, a solution of hydrogen peroxide (_____) and … In the presence of a catalyst such as an iron compound,

What do you see with luminol?Advantages of using Luminol

Allows one to Extremely sensitive - It does not interfere with

Drawbacks Luminol glows even in the presence of Luminol glows in the presence of

So we know its blood – but is it human?

The Precipitin Test They make antibodies They are The serum is called It will cause

Gel Diffusion Test Antigen (blood) and antibodies… They are forced to move towards each other. If they bind to each other,

This is a positive for human blood

DNA TEST DNA testing is the It has made many other tests obsolete.