Radioimmunoassay in Biochemistry

Principles of Radioimmunoassay

• Utilizes competitive binding between a radiolabeled antigen and an unlabeled antigen to measure hormone or drug levels.
• The principle is based on the ability of antibodies to differentiate between similar antigens, allowing quantification of target molecules through the detection of radioactivity.

Purpose of Excess Antibody in Immunoradiometric Assay

• Excess antibody ensures that all available antigens in a sample are bound, enhancing assay sensitivity.
• This minimizes variability in measurement and leads to more accurate quantification of the target analyte.

Function of Enzyme-linked Immunosorbent Assay (ELISA)

• Detects and quantifies proteins, hormones, antibodies, and other compounds in a sample using enzyme-linked antibodies.
• The enzymatic reaction produces a measurable signal, typically a color change, indicating the presence and concentration of the target compound.

Role of a Radioactive Counter in Radioimmunoassay

• Detects and quantifies the level of radioactivity emitted from the radiolabeled antigens and antibodies.
• Provides a means to determine the concentration of the target substance in a sample based on the ratio of bound to free radiolabeled antigens.

Detection Mechanism of Antibody-linked Immunosorbent Assay (ELISA)

• Involves the binding of target compounds to specific antibodies coated on a solid surface, allowing for selective detection.
• A secondary enzyme-linked antibody binds to the target compound, enabling signal amplification through a colorimetric or fluorescent reaction, indicating the presence of the target.

Test your knowledge of Radioimmunoassay, a method for measuring thyroid function and hormone levels in the blood. Learn about the principles and process of Radioimmunoassay in biochemistry.