Quiz 2/Exam 2 Forensic Biology

hemoglobin

the oxygen carrying protein of erythrocytes that belongs to a class of compounds called porphyrins

What is the heme structure?

It is a hexavalent iron atom

What are the two confirmatory crystal tests for blood?

1. teichman crystal test

2. takayama crystal test

How are crystals formed in the Takayama crystal test?

If heme is gently heated with pyridine under alkaline conditions in the presence of a reducing sugar crystals of pyridine ferroprotoporphyrin or hemochromogen are formed.

How are crystals formed in the Takayama crystal test?

Water, pyridine, saturated glucose, and 10% NaOH forms feather shaped pink crystals

What are the five species identification tests?

1. identification of rbc morphology

2. precipitin ring test

3. immunodiffusion

4. immunoelectrophoresis

5. aba card hematrace

micrometry

the measurement of RBCs as precisely as possible in smears made from fresh blood as well as in reconstituted stains

What is the difference between RBCs in birds and reptiles vs. mammals?

RBCs of bird and reptiles — nucleated

RBCs of mammals — enucleated

What is the conclusion of micrometry?

Micrometric method could be used to diagnose blood of mammalian origin and no more.

Whose name is widely associated with precipitin ring test?

Paul Uhlenhuth

What is the difference between single and double immunodiffusion?

Single - one substance (antigen) is being diffused

Double - two substances (antigen and antibody) are being diffused

Who was probably the first to do immunodiffusion using goat serum and antiserum to form precipitate?

Bechold, 1905

What marked the year of double immunodiffusion?

Late 1940s

Who and when was agar gel method described? In what book?

• Ouchterlony, 1968

• Handbook of Immunodiffusion and Immunoelectrophoresis

How did the Ouchterlony Double Immunodiffusion work?

stain extract (antigen) and antiserum (antibody) are placed in adjacent agarose wells and set at RT. Precipitin band is formed when the two samples are from the same species.

Who and when was the term immunoelectrophoresis coined?

Grabar and Williams in 1953

How do ABA card Hematrace cards work?

• sample is applied to a test card well and allowed to migrate to the reagent and react with it

• formation of a colored band indicates human origin

what two animals test positive for the reaction that occurs on an ABA card?

ferret and primates

What is a limitation of the ABA card?

High Dose Hook Effect - caused by high concentration of human Hb