Technical & Learning Resources


Radioimmunoassay (RIA)
  Radioimmunoassay is a technique for measurement of the concentration of hormones. It is based on a principle of serial dilutions. One starts with a combination of radioactively labelled antigen (corresponding to the hormone to be measured) and antibody to that hormone. Then, a specific quantity of unlabelled, or cold antigen is added to the mixture. The unlabelled antigen competes with the radioactive antigen for binding to the antibody and displaces a proportional amount of it. The unbound antigen is separated away (by centrifugation, for example) and the amount of radioactivity remaining is measured (with a Geiger counter). This process is continually repeated, using progressively greater concentrations of unlabelled antigen, and a line graph demonstrating the relationship between concentration of the unlabelled antigen and the radioactivity remaining is constructed. This process creates a standard binding curve. The competitive binding process is then repeated using the biological sample to be tested and by comparison the radioactivity resulting with the standard binding curve, one can deduce the concentration of the hormone in the sample of interest.

In livestock production, RIA is commonly used to measure the concentration of progesterone in blood or milk, which (when repeated at given time intervals) provides an indication of the status of the cow with respect to her oestrous cycle.

- Setting up a Laboratory for Radioimmunoassay (RIA). Manual [pdf, 26 kb].
Enzyme Linked Immunosorbent Assay(ELISA)
Polymerase Chain Reaction (PCR)
DNA microsatellite analysis
Quantification of tannins in tree and shrub foliage
Estimation of microbial protein supply in ruminants
Urea Molasses Multinutrient Blocks
Artificial insemination (AI) of cattle
Selective Breeding and Gene Technologies
General Information
Nuclear Glossary [106 kb, pdf]


DNA Replication [Quicktime]
DNA Structure [Quicktime]
Polymerase Chain Reaction [Quicktime]
Reverse Transcription Polymerase Chain Reaction (RT-PCR) [Flash Movie]
Restriction Enzymes (RE) [Flash Movie]