8-2 Immunoassay Techniques Unit 8: Forensic Serology

Immunoassay Immunoassay is a procedure for detecting or measuring specific proteins or other substances through their properties as antigens or antibodies. In a competitive, homogeneous immunoassay unlabeled analyte displaces bound labelled analyte, which is then detected or measured.

Stimulating Production of Drug Anti-Bodies To produce anti-bodies capable of reacting with drugs, the analyst combines the specific drug with the protein and inject this combination into an animal such as a rabbit.

Detecting Abused Drugs This drug-protein complex acts as an antigen, stimulating the animal to produce anti-bodies.

Blood Serum The recovered blood serum of the animal now contains anti-bodies that are specific or nearly specific to the drug.

Antigen When an animal is injected with an antigen its body produces a series of different anti-bodies, all of which are designed to attack some particular site on the antigen of interest.

Blood Serum The recovered blood serum of the animal now contains anti- bodies that are specific or nearly specific to the drug. These anti-bodies are known as polyclonal antibodies.

Blood Serum A more uniform and specific collection of anti-bodies design to combine with a single antigen site can be manufactured. Such anti-bodies are known as monoclonal antibodies.