3/30/15Aim: How can we describe the components of blood? Do Now:1-how was blood typing discovered?...
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3/30/15Aim : How can we describe the components of blood? Do Now :1-how was blood typing discovered? 2- Who used it in forensics first? 3-is blood individual or class evidence? EXPLAIN HW : Read Chapter 11, read pages 306-308 page 329 – 330 questions 2,5,6
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Transcript of 3/30/15Aim: How can we describe the components of blood? Do Now:1-how was blood typing discovered?...
3/30/15Aim: How can we describe the components of blood?
Do Now:1-how was blood typing discovered?
2- Who used it in forensics first?3-is blood individual or class evidence?
EXPLAIN
HW: Read Chapter 11, read pages 306-308 page 329 – 330 questions 2,5,6
Discovery of human blood type
• 1901 Dr. Karl Landsteiner discovered that blood can be divided into different categories
• (A, B, AB, and O)
Leone Lattes 1887-1954Lattes that was intrigued and
thought that these groupings could be used for identification purposes.
He devised a procedure which determined the blood group of a dried bloodstain
that it could be checked against potential suspects
A. Serology• Serology – the study of bodily fluids.• Blood is the most common bodily fluid found at crime
scenes. Study of blood is hematology
How much blood do we have in our
bodies?
Human body
• About 7% of body weight is made up of blood– 5.5 liters about 11.6 pints
• 3 liters of that is plasma
Parts Of Blood• Plasma
• Red Blood Cells
• White Blood Cells
• Platelets
Q: Think back to Living Environment. What is the role of each blood part?
1-Plasma• Made up mostly of
water (92%)• Dissolved all water
soluble compounds• Glucose, ions,
metabolites, alcohol, minerals, proteins, hormones etc
How can we describe plasma?
1. Plasma a. liquid portion of blood. b. 55% of total blood
volume. c. 90% water. d. 10% salts, proteins, glucose,
amino acids, enzymes, hormones, and cellular wastes
Why are red blood cells important?
2. Red Blood Cells - erythrocytes a. Small donut shaped cells b. Contain hemoglobin (iron) – the red oxygen
carrying pigment. c. Mature RBC’s have NO NUCLEUS
d. Control blood type = NO DNA!!
Why are RBC’s important to investigators?
Structure of Red blood cell
• NO NUCLEUS• Contain the protein
hemoglobin– Made of 4 polypeptide chains
each with a binding site for Iron (Fe)
• Which creates 4 binding sites for oxygen or Carbon dioxide and carbon monoxide
• Your body makes about 2 million RBC every second
Science fact
5 million RBC’s can fit on the head of a pin, and over 5 trillion RBC’s are present in your body at any given
time.
Why are white blood cells important to investigators?
3. White Blood Cells - leukocytes a. Large cells with a nucleus = DNA b. Less numerous than RBC’s. c. Defenders of the body.
Tuesday 3/31/15
• AIM: how is human blood typed?• DO NOW: 1- Take out the homework that was
assigned Thursday q 2,5,6 pg 330• 2- List the 4 parts of blood • 3- Explain how human blood can be both
individual and class evidence• 4- which part of the blood is responsible for type?• HOMEWORK: Text page 330 q 3 and 4
Which of the cells have Class or Individual Characteristic? Why?
Class Individual
Red blood Cells White blood Cells
=
Explain which parts of the blood would be most useful to a forensic investigator. Be sure to explain why.
How can we describe Platelets?
4. Platelets - thrombocytes
a. Smaller than RBC’s and WBC’s
b. blood clotting
Platelets: clot damaged blood vessels
How is blood used as evidence?B. Blood in Forensics
– Blood samples – Analyzed to determine BLOOD TYPE and DNA, which can be matched to possible suspects.– Blood droplets – Analyzed to give clues
to the location of a WOUND, movement of a VICTIM, and type of INJURY.
– Blood spatter – Analyzed to determine PATTERNS that give clues to how a crime happened.
Serology covers all of these
What do we know about blood types and blood typing?
According to the ABO blood typing system there are four different kinds of blood types: A, B, AB or O (null).
ABO blood grouping system
•The differences in human blood are due to the presence or absence of certain protein molecules called antigens and antibodies.
•The antigens are located on the surface of the RBCs and the antibodies are in the blood plasma.
•Individuals have different types and combinations of these molecules.
•The blood group you belong to depends on what you have inherited from your parents.
What are the different blood groups?
How is blood type determined? RBC’s are covered by protein molecules called Antigens. The antigens determine the blood type.
Antibody
• Defend against foreign antigens• Float in the plasma
Rh factor: rheusus factor
• Separate gene• If you have it you are Rh + and you make the
protein• If you don’t have it you are Rh – and you don’t
make the protein
Aim: How is blood type determined?
Do Now:1. Describe why red blood cells
are forensically important.2. Explain how human blood type
is determined3- list the 4 blood types HW:QUIZ tomorrow
Rh factor: rheusis factor
• Named after the rheusis monkey• Determines positive or negative blood• If you have the gene you express the protein
and have + blood• If you don’t have the gene you are Rh –• This becomes a problem at child birth• If mom + blood mixes with babies – blood the
baby could die
Ryan the rheusus monkey
Rh Factor
• Rh is another antigen found on RBC’s.
• If the Rh antigen is present the persons blood type is considered positive, if absent the person is negative.
Ex. O+ or AB-
In 1940, Landsteiner and Weiner reported the discovery of the Rh factor by studying the blood of the Rhesus monkey. 85 percent of Caucasians, 94 percent of Black Americans, and 99 percent of all Asians are Rh positive.
ABO and Rh blood type frequencies
• O-positive: 38 percent.• O-negative: 7 percent.• A-positive: 34 percent.• A-negative: 6 percent.• B-positive: 9 percent.• B-negative: 2 percent.• AB-positive: 3 percent.• AB-negative: 1 percent.
Blood typing vocabulary
1. Antigen – Protein marker found on Red Blood Cell. ID’s the cell. (ex. – if a cell has the A antigen, then it is a type A blood cell).
2. Antibody – Found in blood plasma and used by body to fight off harmful substances. Anti-A or Anti-B – if body has B antibody, it will fight ALL cells that have that marker.
Antigen-antibody response• If a foreign antigen enters the body, it is
attacked by antibodies• Causes agglutination: blood clotting
Who is the Universal Donor/Receiver?
1. Universal Donor – TYPE O, can give blood to anyone.
2. Universal Receiver – TYPE AB, can receive blood from anyone.
- Which would you rather be??
• Illustration of the forward and reverse grouping reaction patterns of the ABO groups using a blood group tile
http://www.bh.rmit.edu.au/mls/subjects/abo/resources/genetics1.htm
When RBCs carrying one or both antigens are exposed to the corresponding antibodies, they agglutinate; that is, clump together. People usually have antibodies against those red cell antigens that they lack.
Human RBC before (left) and after (right) adding serum containing anti-A antibodies. The agglutination reaction reveals the presence of the A antigen on the surface of the cells.
http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/B/BloodGroups.html
Blood group AIf you belong to the blood group A, you have A antigens on the surface of your RBCs and B antibodies in your blood plasma.
Blood group BIf you belong to the blood group B, you have B antigens on the surface of your RBCs and A antibodies in your blood plasma.
AB0 blood grouping system
Blood type A • Has A antigens, and B antibodies.
Blood type B• Has B antigens and A antibodies
Blood group ABIf you belong to the blood group AB, you have both A and B antigens on the surface of your RBCs and no A or B antibodies at all in your blood plasma.
Blood group OIf you belong to the blood group O (null), you have neither A or B antigens on the surface of your RBCs but you have both A and B antibodies in your blood plasma.
Blood Type AB Has both antigens (A + B) and
neither antibodies.
Blood Type O• Has neither antigen and both
antibodies A and B
Blood typing activity• In order to complete the activity we need to learn a little
vocab…1.Antigen – Protein marker found on Red Blood Cell. ID’s the
cell. (ex. – if a cell has the A antigen, then it is a type A blood cell).
2.Antibody – Found in blood plasma and used by body to fight off harmful substances. Anti-A or Anti-B – if body has B antibody, it will fight ALL cells that have that marker.Using this info, figure out which blood types can be safely
transfused.
Monday 4/13/15
• AIM: how are blood transfusions determined?• DO NOW: 1-What is the universal receiver and
why?• 2- What is the universal donor and why?• HOMEWORK: Text read page 317. answer the
following:• 1-How do you package and store blood evidence?• 2- Who is Dr. Sam Sheppard and what was his
crime?
Who is the Universal Donor/Receiver?
1. Universal Donor – TYPE O, can give blood to anyone.
2. Universal Receiver – TYPE AB, can receive blood from anyone.
- Which would you rather be??
AB is the universal receiver because it has NO antibodies so it will not attack but also it has
both antigens so none are foreign
O is the universal donor because it has no antigens so it is not
recognized by antibodies
ABO blood groups in the US population
BLOOD TYPE ANTIGENS
(ID tags)
ANTIBODIES
(Weapons in blood)
A
B
AB
O
In your notes complete the chart Blood type chart
BLOOD TYPE ANTIGENS
(ID tags)
ANTIBODIES
(Weapons in blood)
A
B
AB
O
AA
BB
A and BA and B
nonenone
Anti - BAnti - B
Anti - AAnti - A
nonenone
Anti-A & Anti-BAnti-A & Anti-B
Blood type chart
What happens when a person with blood type B receives a
transfusion from blood type A? Antibody A from blood type B will attack antigen A on the RBC of the
transfused blood type A
Safe Blood Transfusions
Recipient Can safely receive from…
Type A
Type B
Type AB
Type O
Safe Blood Transfusions
Recipient Can safely receive from…
Type A
Type B
Type AB
Type O
A, O
B, O
A, B, AB, O
O only
What happens if you give a victim the wrong blood
type?
Agglutination = +
No agglutination = -
This fact helps investigators identify sample blood types.
Agglutination: antigen antibody response in blood typing
Let’s see if you can save these patients
Blood Typing
Summary
1. How is blood type determined?2. I have type O+ blood. What antigens do I have
on my RBC’s? What antibodies are in my blood?3. Is it safe to give someone with type B blood a
transfusion of type AB? Why or why not?4. From which types can type B blood safely receive
samples from.5. Which blood type is considered the universal
receiver?
Is it safe to give someone with type B blood a transfusion of type AB? Why or why not?
Tuesday 4/14/15• AIM: How is blood analyzed from the crime scene?• DO NOW: IN DETAIL explain what would happen if a
person with blood type O received a transfusion from blood type AB.
• HOMEWORK: Text read page 317. answer the following:
• 1-How do you package and store blood evidence?• 2- Who is Dr. Sam Sheppard and what was his
crime? •
