Serology I Flashcards
Serology
Study of serum and other bodily fluids
What fluids might you find in a crime scene?
Blood, sweat, tears, semen, saliva, vaginal fluids
How many people are Secretors
80%
What are secretors
People you can tell the blood type from sweat and tears
What is alcohol used for in Kastle-Meyer?
cleaning up the area AND Increasing sensitivity to better expose the hemoglobin
What does H2O2 (hydrogen peroxide) do in kastle meyer?
Hemoglobin frees oxygen w/in H2O2, chemical oxident
What is phenolphthalein used for in kastle-meyer?
Color indicator, turns pink when oxidized
What is hemoglobin?
Oxygen carrying pigment of red blood cells
What does hemoglobin do?
Carries oxygen to tissues
What makes mammal blood cells different from non mammals?
Mammal blood cells are circular
Antigens
Proteins on the surface of your red blood cells
Agglutination
Blood clotting/coagulation
What are the blood types?
+/- A, B, AB, O
What floats in the plasma of blood?
Antibodies (“Bouncers”, goes against incompatible)
Why is there a dent in the human blood cell?
A nucleus used to be there, but it degraded early in its life
What creates blood cells?
Bone marrow
Do blood cells reproduce?
No, bc no nucleus
What is a spleen?
“Red/white blood cell cemetery”,
What determines your blood type?
Parents/inheritance
What do blood types mean?
Specific antigens attached to the surface of your red blood cells
What does AB blood have?
Both types of Antigen
What is O blood type?
No antigens
RH factor
An antigen that makes a blood type Positive. If you have it you’re positive, if you don’t then you’re negative
What makes O- special?
No antigens, very neutral (No RH factor OR antigens). Universal
What happens if you put two blood types together that are incompatible?
Agglutination/everything gels up like it’s clotting. Death will occur.
Will an antibody (with A+) accept A-?
Yes
Will an antibody (With A+) accept B+
No, it will reject it (B present)
Will an antibody (with A+) accept AB+?
No, it will reject it (B is present)
Will an antibody with A+ accept O+
Yes, it will accept it (no B present)
Does B- have RH?
No (negative)
If you have a B- blood, what antibodies will be in the plasma?
Anti-A, anti-RH
Will B- accept A+ blood?
No (RH present, A present)
Will B- accept O+?
No (RH present)
What blood types will O- accept?
NONE except O-
What blood types will AB+ accept?
ALL blood types
What is AB+ known as?
the Universal Recipient (ANYONE can donate to you)
What is O- known as?
The universal Donor (You can donate to ANYONE)
Putrefaction
decay
What are antigens known as?
“Surface Markers”; they trigger immune responses (coagulation/agglutination)
What do antibodies do?
Interact with antigens, if they are against them then they will destroy them
What antibodies does O- have?
Anti-A, Anti-B
Why does nothing happen in a kastle-meyer test if no hemoglobin is present?
No H2O2 to break up into 2H202 and O2
Why do you test something you know has blood on it if it’s blood?
To make sure the test is working and to see the difference between a positive and negative result.
What is the first step in DNA fingerprinting?
Add restriction enzymes to DNA Sample (cuts long DNA strands)
Step 2 of DNA fingerprinting
Pour aragose gel into tray on lab counter (Acts as a molecular strainer)
Step 3 of DNA fingerprinting
Electrophoresis (moves molecules with electric current) (DNA is negative, so gel acts as a strainer for the DNA as it moves to the positively charged tray
Step 5 of DNA fingerprinting
Place nylon membrane on top of gel (easier to work with, DNA moves to membrane)
Step 6 of DNA fingerprinting
Add probes to the nylon membrane (probes are radioactive and attach to certain DNA fragments in a sequence)
Step 7 of DNA fingerprinting
Place X-ray on top of nylon film (exposes radioactivity from the probes) and develop
who discovered human blood types
Landsteiner
DNA fragments separate according to ___ during DNA fingerprinting
size
The fragments visualized during DNA fingerprinting
bands
the process used to separate bands of DNA
gel electrophoresis
test performed at a crime scene; a screening test
presumptive
dna fingerprint database
CODIS
confirmatory test for identifying blood cells
microscopic analysis
test performed in a secure, controlled lab setting
confirmatory
Statistical analysis is based on the most ____ portions of DNA
unique
If the swab turns pink ____ you have a positive result on the kastle-meyer test
immediately
the oxygen during the K/M test is supplied by the
hydrogen peroxide
Why is it necessary to type the victim’s blood when investigating crime
the crime scene could just have the victim’s blood (especially if both victim and evidence are the same blood type
What is the result if both the victim and the suspect have the same blood type?
inconclusive
