1. Radioimmunoassay (RIA): A Remarkably Sensitive Bioassay Sarah Dekat NCSS 2006

2. Biochemistry Principles

3. Radioimmunoassay Procedure

4. Standard Curve & Unknown Sample

5. Characteristics of Binder and Ligand Availability  Synthetic  Natural – Produced From Animals  Monoclonal Antibodies Purity – Competing Reactions with Impurities Stability – Store in Albumin Serum Specificity – Binding Constant

6. Characteristics of Tracer Must Have Similar Binding Properties as Unlabeled Ligand Internally Labeled Ligand  14 C and 3 H Externally Labeled Ligand  131 I and 125 I By-Products or Incomplete Synthesis  Purification by chromatography (gel filtration)

7. Separation of Bound and Free Ligand Electrophoresis Gel Filtration Adsorption Chromatography Fractional Precipitation  Centrifugation  Filtration Partition Chromatography  Dialysis

8. Increasing Assay Precision

9. Sensitivity – Decrease [Ligand]

10. Sensitivity – Decrease [Binder]

11. Comparison of Assays Enzymeimmunoassays (EIA)  millimolar Fluoroimmunoassays (EIA)  micromolar Radioimmunoassays (EIA)  nanomolar to picomolar

12. Applications of Radioimmunoassays Endocrinology  Insulin, HCG, Vasopressin  Detects Endocrine Disorders  Physiology of Endocrine Function Pharmacology  Morphine  Detect Drug Abuse or Drug Poisoning  Study Drug Kinetics

13. Applications of Radioimmunoassays Epidemiology  Hepatitis B Clinical Immunology  Antibodies for Inhalant Allergens  Allergy Diagnosis Oncology  Carcinoembryonic Antigen  Early Cancer Detection and Diagnosis

14. Summary Based on Simple Biochemistry Principles Establish Ideal Binder and Ligand Synthesize Tracer Ligand Separation of Bound and Free Parts High Precision and Sensitivity Powerful Applications to a Wide Range of Medical Fields