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

Serology

Serology 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 body

1. 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 TransfusionsAntigens 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 Groups

Type / Anitgen / Antigen / Can receive from / Can donate to
A / A / B / A, O / A, AB
B / B / A / B, O / B, AB
AB / A and B / NONE / A, B, O / AB
O / 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 / O
A
B
O

Transmission of our traits

Allele Combinations / Blood Type
(phenotype)
AA + AO
BB +BO
AB
OO

Paternity Testing

.

If a man and child share the HLA markers, …

The Haptoglobin marker +

DRUG - DETECTION

Hypothesis:

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.