1. Forensic Biology by Richard Li
Chapter 7: Species Identification
Forensic Biology by Richard Li

2. General Considerations
Species Identification:
In the past, done by serological methods
Now, accomplished by DNA quantitation
Can be a good screening method for unnecessary tests
Can be used at the crime scene
Necessary in animal cases
Use primary and secondary binding assays
Forensic Biology by Richard Li

3. Types of Antibodies Antihuman serum Albumin Hemoglobin antibody
Glycophorin A
Forensic Biology by Richard Li

4. Titration of Antibodies
Series of dilutions of antiserum are made and each dilution is then tested for activity using either precipitation or agglutination methods
Titer- the reciprocal of the highest dilution giving a positive reaction.
Forensic Biology by Richard Li

5. Specificity
Most antihuman sera usually have cross-reactivity with higher primates
Crimes involving primates are rare
Forensic Biology by Richard Li

6. Optimal Conditions Proper buffer system Ionic strength
Intro of polymers
Temperature pH
Forensic Biology by Richard Li

7. Assays Immunochromatographic Assays
Identification of human hemoglobin protein
Hexagon OBTI
ABAcard HemaTrace
Identification of human glycophorin A protein
RSID-Blood
Forensic Biology by Richard Li

8. Assays Precipitation-based assays Ring assay Ouchterlony assay
Identity
Non-identity
Partial identity
Crossed-over electrophoresis
Forensic Biology by Richard Li