UNIT 6 SEROLOGY

Students will investigate the characteristics of blood, blood testing, and bloodstain analysis.

VOCABULARY Erythrocytes Leukocytes Thrombocytes Plasma Antigen RBC WBC Rh Factor Bloodstain Pattern Analysis Surface Tension Low-velocity impact splatter (LVIS) Medium-velocity impact splatter (MVIS) High-velocity impact splatter (HVIS) Drip pattern Cast off pattern Swipe/smear pattern

Spurt pattern Expirated pattern Agglutinate (verb) Luminol Blue Star Hydrogen peroxide Kastle-Meyer Passive spatter Transfer spatter Projected spatter

IDENTIFY THE COMPONENTS AND PHYSICAL PROPERTIES OF BLOOD

(ERYTHROCYTES, LEUKOCYTES, THROMBOCYTES, AND PLASMA)

Solid portion of the bloodA. Erythrocytes1. Red blood cells (RBC).2. Contain hemoglobin that transports the oxygen and carbon dioxide.3. Concave in structure.4. Approximately 30 trillion in the blood.

IDENTIFY THE COMPONETS AND PHYSICAL PROPERTIES OF BLOOD

B. Leukocytes1. White blood cells (WBC).2. Provide immunity for the body

and produce antibodies.3. There are 5 types of white blood

cells.4. Approximately 430 billion in the

blood.

IDENTIFY THE COMPONETS AND PHYSICAL PROPERTIES OF BLOOD

C. Thrombocytes1. Platelets (pieces of larger cells).2. Responsible of starting the

clotting process by making fibrin to form a clot.

IDENTIFY THE COMPONETS AND PHYSICAL PROPERTIES OF BLOOD

Liquid portion of the bloodA. Plasma

1. Fluid portion of the blood that carries the RBC, WBC, and platelets.

2. 55% of blood is the plasma.3. Made up of 90% water and 10%

metabolites (salt, ions, and proteins).

ANTIGENS AND ANTIBODIES THAT DETERMINE ABO BLOOD TYPES AND THE RH FACTOR

ABO blood classification systemA. Antigens1. Proteins found on the surface of every RBC. 2. There are over 100 different antigens in the human blood.3. Two of the antigens, labeled as A and B, are the ones used on the RBC surface to determine blood type.

ANTIGENS AND ANTIBODIES THAT DETERMINE ABO BLOOD TYPES AND THE RH FACTOR

If antigen A is present a person is A blood type.

If antigen B is present a person is B blood type.

If both antigens A & B are present a person is AB blood type.

If neither antigens A & B are present a person is O blood type.

ANTIGENS AND ANTIBODIES THAT DETERMINE ABO BLOOD TYPES AND THE RH FACTOR

Antibodies Manufactures by some of the WBC and found in the blood

serum. Function is to attack any invader (antigen) that enters the

bloodstream that does not belong in your system. A person has antibodies again antigens that are not

found on the surface of their own RBC. Rh Factor (Rhesus factor)

Antigen found on the surface of a RBC. If a person has the Rh antigen they are Rh positive (Rh+). If a person does not have the Rh antigen they are Rh

negative (Rh-).

DETERMINE GENETIC PROBABILITIES USING BLOOD TYPES

Punnet Squares: A parent passes on one of two genes for blood type to the offspring. One of two genes is also passed on for the Rh factor. In order to be recessive in type or Rh, BOTH genes must be recessive. Using a Punnet square can determine if a blood type is possible in an offspring. This is useful in many ways, one of the most common being paternity.

DETERMINE GENETIC PROBABILITIES USING BLOOD TYPES

If a child’s blood type is AB+, the mother’s type is AB+ and the father’s type is O-, could the “father” be the genetic father? BAO

O

GENETIC PROBABILITIES Typical blood typing distribution in the

United States.

www.bloodbook.com/world-abo.htmlBlood Type PercentageA 40%B 11%AB 4%O 45%Rh+ 85%Rh- 15%

PROPERTIES OF BLOOD Blood Volume

On average, accounts for 8 % of total body weight

5 to 6 liters of blood for males 4 to 5 liters of blood for females A 40 percent blood volume loss, internally

or/and externally, is required to produce irreversible shock (death).

A blood loss of 1.5 liters, internally or externally, is required to cause incapacitation.

BLOOD TYPING USING SALIVA Blood typing can be done on people who

are called “secretors” 80% of the population are secretors. A secretor is a person who has the gene to

secrete blood type substances (A, B & H)in a soluble glycoprotein form in their body fluids, like saliva, tears, gastric juice, etc.

The “A” and “B” substances are derived from the “H” substance

BLOOD TYPING USING SALIVA If cells do not clump, the person is a

secretor If the cells clump (agglutination), the

person is a non-secretor Lectin is a plant substance that reacts

with blood group substances The lectin will indicate if an H

substance is present in the blood (an H substance is the A or B)

BLOOD TYPING USING SALIVA If H group is present, then anit-A serum

and anti-B serum can be added to determine blood group

BLOOD DETECTION LABS Before blood can be used as evidence, it must

first be confirmed to be blood. Test 1: Presumptive Blood test. This test

shows the presence of hemoglobin. It is not human specific.

“Every contact leaves a trace.” Blood evidence is extremely important in

forensics. It can be used to determine the nature of the crime, blood types, DNA, recreate a crime scene, etc.

PRESUMPTIVE BLOOD TEST However, running blood tests and DNA tests

is very time consuming and expensive. If a sample is sent to a lab for processing, it is best to know if the sample is most likely blood or not.

A presumptive blood test “presumes” a substance is blood if it reacts to chemicals in a particular way.

The most common presumptive test that is run is the Kastle-Meyer Test .

KASTLE-MEYER TEST Kastle-Meyer is quick, inexpensive, easy

and does not compromise the integrity of the sample, like DNA. It is very sensitive, 1:10,000. One drop of blood diluted 10,000 times with water can still be detected.

It does not distinguish between human and animal blood. It detects the iron in hemoglobin, so other products with iron could also give a positive result.

Products used: Alcohol (cleans sample and exposes more hemoglobin), phenolphthalein (changes color with oxidation – tells you if the test is bad and you need to redo it), hydrogen peroxide (releases extra oxygen, causes the pink color if oxygen is released from the hemoglobin)

BLOOD DETECTION LABS Test 2: Luminol Test. This test shows where

blood has been present but wiped away. It can also react to a number of substances such as copper or copper-containing alloys, and certain bleaches; and, as a result, if a crime scene is thoroughly cleaned with a bleach solution or horseradish, residual cleaner will cause the entire crime scene to produce the typical blue glow, effectively camouflaging any organic evidence, such as blood. Luminol reacts with fecal matter, causing the same glow as if it were blood.

Surface TensionThe elastic like property of the surface of the liquid that makes it tend to contract,caused by the forces of attraction between the molecules of the liquid.The cohesive forces tend to resist penetration and separation.

BLOOD SPATTER Bloodstain Pattern Analysis: is the

examination of the shapes, locations, and distribution patterns of bloodstains, in order to provide an interpretation of the physical events which gave rise to their origin.

Based on the premise that all bloodstains and bloodstain patternsare characteristic of the forces that have created them.

FBI website

The determinations made from bloodstain patterns at the scene or from the clothingof principals in a case can be used to:

Confirm or refute assumptions concerning events and their sequence:Position of victim. (standing, sitting, lying)Evidence of a struggle. (blood smears, blood trails) n

Confirm or refute statements made by principals in the case:Are stain patterns on a suspects clothing consistent with his reported actions?Are stain patterns on a victim or at a scene consistent with accounts given by witnesses or the suspect?

FBI website

BLOOD SPATTER At a crime scene the blood spatter patterns are

photographed before the blood is collected so that the suspects account can be proved or disproven. The photographs will allow for an interpretation and reconstruction of what happened.

A. Size of blood splatter 1. Recorded with micro scales visible in

photographs. 2. The smaller the drop the faster the movement of

the blood.

BLOOD SPATTERB. Shape of blood spatter

1. Recorded with micro scales visible in photographs. 2. Shape of the mark where it lands reveals the direction in which the drop was traveling and the amount of force it was projected with.

C. Directionality of blood spatter1. The pattern that indicated the direction the blood was traveling when it hit the target surface.2. Established from the geometric shape of the bloodstain.

 

BLOOD SPATTER Velocity is the speed at which

something travels with a direction. A. Low-velocity impact spatter (LVIS)

1. Caused by low-speed impact or force to a blood source.

2. Velocity may be up to 5 feet per second or 1.5 meters per second.

3. Drop size is larger than 3 millimeters.

BLOOD SPATTER B. Medium-velocity impact spatter

(MVIS) 1. Cause by medium-speed impact or force

to a blood source. a. Blunt force trauma, beating or a stabbing.

2. Velocity is about 25 feet per second or 1.5-7.5 meters per second.

3. Drop size or stain of 1-3 millimeters.

BLOOD SPATTER C. High-velocity impact spatter (HVIS)

1. Caused by high-speed impact or force to a blood source.

a. Gunshot, explosive devices, a cough or sneeze.

2. Velocity may be 100 feet per second or 30 meters per second.

3. Drop size is a mist like appearance forming drops <1 millimeter.

BLOOD SPATTER PATTERNS: PASSIVE Passive Bloodstains are drops

created or formed by the force of gravity acting alone.

Drops, drip patterns, pools, clots Drip pattern: A blood stain pattern that

results from blood dripping into blood.

BLOOD SPATTER PATTERNS: TRANSFER A transfer bloodstain is created

when a wet, bloody surface comes in contact with a secondary surface.

Contact bleeding Swipe or smear Wipe smudge

BLOOD STAIN PATTERNS: PROJECTED Projected bloodstains are created

when an exposed blood source is subjected to an action or force, greater than the force of gravity. (Internally or Externally produced)

Cast-off Arterial spurt Expirated

BLOOD SPATTER PATTERNS SUMMARY

A. Drip pattern: A blood stain pattern that results from blood dripping into blood.

B. Cast-off pattern: A blood stain pattern created when blood is released or thrown from a moving a blood bearing object.

C. Transfer or Contact pattern: A blood stain pattern created when a wet, bloody surface comes in contact with a second surface.

Swipe pattern: The transfer of blood from a moving source into an unstained surface; the direction of travel may be determined by the feathered edges.

Spurt pattern: artierial spurts, appear as lines of blood Expirated pattern: Blood that is blown out of the nose, mouth,

or a wound as a result of air flow, which is the propelling force.

WHAT TYPE OF BLOOD SPATTER PATTERN?

BLOOD SPATTER VOCAB CARDS IN the Forensics book, pages 231-232,

there are 35 blood spatter terms. Create flashcards for each term.

For the terms which describe how blood spatter looks, create a picture image of what it looks like using water color paints- so your flashcards for the following terms will have a word, a definition and a painted picture example

BLOOD SPATTER VOCAB CARDS The following terms need to have a painted

picture: arterial spurting, bloodstain, cast-off pattern, contact stain, drip pattern, expirated blood, flow pattern, HVIS, impact pattern, LVIS, MVIS, misting, parent drop, passive drip, satellite spatter, spatter, spine, swipe pattern, transfer pattern, void, wipe pattern.

For HVIS, MVIS, LVIS, simple put a “drop” mark with the brush that is the right size in diameter.

DIRECTIONALITY OF BLOOD SPATTER When a droplet of blood strikes a surface

perpendicular (90 degrees) the resulting bloodstain will be circular.That being the length and width of the stain will be equal.

Blood that strikes a surface at an angle less than 90 degrees will be elongated or have a tear drop shape.Directionality is usually obvious as the pointed end of the bloodstain ( tail ) will alwayspoint in the direction of travel.

IMPACT ANGLE DETERMINATION ANGLE of IMPACT is the acute

angle formed between the direction of the blood dropand the plane of the surface it strikes

By utilizing trigonometric functions its possible to determine the impact angle for any given blood droplet.

SIN 0 = opp (a) hyp (c)

SIN < = Width (a) 1.5cm Length (c) 3.0cm Width (a) 1.5cm = SIN < Length (c) 3.0cm

0.5 = SIN <

< = 30 degrees

DETERMINING ANGLE OF IMPACT Complete the assignment “Angle of

Impact”

POINT OF CONVERGENCE AND ORIGIN DETERMINATION

The common point, on a 2 dimensional surface, over which the directionalityof several bloodstains can be retraced.

Once the directionality of a group of stains has been determined,it's possible to determine a two dimensional point or area for the group of stains.

CRIME SCENE ANAYLSIS OF BLOOD SPATTER

http://www.bloodspatter.com/cases.htm Answer the questions the police would

ask you. Give an explanation of events for each

picture

COLLECTING BLOOD STAIN EVIDENCE B. Dry blood stain collection

1. Moisten sterile cotton-tip with sterile water. 2. Rub over the blood stain until blood is picked up. 3. Allow cotton swab to air dry. 4. Package in a clean paper or envelope. 5. Seal package with tamper resistant tape. 6. Label with exhibit number, initials and date.

Or 1. Tape-lift the bloodstain, scrape bloodstain into paper packet or

cut the portion of the stain from the object it is on. 2. Package in a clean paper or envelope. 3. Seal package with tamper resistant tape. 4. Label with exhibit number, initials and date.

COLLECTING BLOOD STAIN EVIDENCE C. Large object blood stain collection

1. Cut out the blood stained areas. 2. Allow for it to air dry. 3. Package in paper bags or paper

wrapping. 4. Seal package with tamper resistant

tape. 5. Label with exhibit number, initials and

date.

BLOOD TESTS TO IDENTIFY BLOOD PRODUCTS

A. Luminol- Used if a high-intensity light beam does not reveal blood at a crime scene after it has been cleaned. 1. Luminol is a reagent that makes blood identifiable. 2. Luminol is sprayed in a dark room to reveal drops of blood. 3. Turns a fluorescent blue glow when it comes in contact with

blood. 4. Reacts with the iron that is found in the hemoglobin of

blood. 5. Glow will last 30 seconds and must be documented with a

photograph. 6. False positive can occur with metals, bleach and some

plaster on walls.

BLOOD TESTS TO IDENTIFY BLOOD PRODUCTS

B. Hydrogen peroxide- A strong oxidizing agent. 1. The heme in hemoglobin of RBC breaks down the peroxide. 2. This reaction caused the production of oxygen that causes the

stain to turn blue in color. 3. Often hydrogen peroxide is used with the Kastle- Meyer Test.

C. Kastle- Meyer Test (K-M Test)- A blood test that uses the chemical indicator called phenolphthalein to detect the presence of hemoglobin. 1. A blood sample is collected on a cotton-tipped swab and a drop of

phenolphthalein is added to the tip. 2. After a few seconds hydrogen peroxide is applied to the swab. 3. If the swab turns bright pink rapidly it is positive for blood. 4. After 30 seconds the swab will naturally turn pink as it oxidizes on

its own in the air.

SEMEN Semen and saliva are other body fluids which are

commonly found at crime scenes. We will be examining semen from a bull. First, examine

the live sperm in the microscope. Draw and describe what you see. How would a sperm count be made? How could a sperm count play a role in being evidence? (class or individual)

Using black light, examine the fabric to see if body fluid is present (in this case, bull semen). Describe the methods you used. Describe what you see.

How would this evidence be collected and sent back to the lab?

CAREERS IN BLOOD A. Phlebotomist Collects blood samples by venipuncture.

1. Level of education: High school diploma and accredited training program licensure.

2. Credentialing requirements: Each state decided licensing.

3. Employment opportunities and career growth potential: High demand.

4. Workplace environments: Hospital, laboratory, clinics, and doctors office.

5. Salary: $12.00/hour

CAREERS IN BLOOD B. Forensic Serology DNA Criminalist Tests blood and other body fluids found at a crime

scene. 1. Level of education: Minimum of a Bachelors degree;

often a Masters degree or Doctoral degree. 2. Credentialing requirements: None. 3. Employment opportunities and career growth

potential: Good in current job market. 4. Workplace environments: Law enforcement agencies,

crime labs, Military agencies and medical professional agencies.

5. Salary: $32,000 year/ average

CAREERS IN BLOOD Serology Technician Work in the collection, testing, and analysis of

evidence from a crime scene. 1. Level of education: Minimum of an Associate’s degree;

often a Bachelors degree or Masters degree. 2. Credentialing requirements: Must go through a

state/national accreditation training program. 3. Employment opportunities and career growth

potential: Good in current job market. 4. Workplace environments: Law enforcement agencies,

crime labs, government agencies and laboratories. 5. Salary: $50,000 year/ average

THE CASE OF LOIS MCARTHUR This simulated crime scene will require

you to use your knowledge of hair, fiber, trace and blood evidence to solve.

TEST REVIEW