Forensic Analysis of Blood- Part 1 Flashcards
Why should body fluids be identified?
- To help prove an element of a crime
- To provide a linkage between individuals/scenes/objects
- To help interpret genetic data
- To assist in the reconstruction of events
What are the 2 categories of identification tests?
- Presumptive Tests
- Confirmatory Tests
What are Presumptive Tests for?
To screen specimens that MIGHT contain the substance of interest
What are Confirmatory Tests for?
To CONFIRM that the specimen contains the substance of interest
(Are entirely specific for the substance for which it is intended)
What is the initial examination designed for?
Evaluating stains for possible evidentiary value
Definition of Blood…
Slightly alkaline fluid consisting of water, cells, enzymes, proteins, and inorganic substances
What is the function of Blood?
Circulates through the body to supply nutrients and oxygen to the body, and removes waste
What are the 3 types of Blood Cells?
- Red Blood Cells (erythrocytes)
- White Blood Cells (leucocytes)
- Platelets (thrombocytes)
What is Plasma?
The liquid portion of blood
What is Plasma composed of?
Water, proteins, and electrolytes
Antigens (Ag)
Proteins and carbohydrates that are responsible for blood type characteristics
Antibodies (Ab)
Located in the plasma
What are the most common agents for colorimetric assays?
- Phenolphthalein (Kastle Meyer)
- Leucomalachite green (LMG)
- Hemastix
- Benzidine Dertivatives (TMB)
What tests are used to determine species origin of blood?
- Ouchterlony test (anti-hemoglobin)
- RSID (anti-glycophorin A)
- ABAcard Hematrace (anti-hemoglobin)
What is the High Dose Hook Effect?
NEED TO KNOW!
Describes a WRONG LOW measurement of analytes which are present in the specimen in a VERY HIGH concentration
