Immunoradiometric assay (IRMA) is an immunoassay that uses radiolabeled antibodies to bind sample antigens. In this assay, the antibody is labeled using a radioisotope. The radiolabeled antibody binds to the antigen to form an antigen-antibody complex. Finally, the antigen-bound portion is radiometrically determined.
Based on the principles of immunoradiometric assays, we describe experimental protocols for the quantification of compound concentrations using radiolabeled specific antibodies. We provide IRMA-related methods and troubleshooting to provide standardization and accuracy for your actual measurements.
|Stages||Solutions and Reagents|
|Preparation||Standards, dilution buffer|
|Antigen-antibody reaction||Solid-phase carrier materials, capture antibody, labeled antibody, dilution buffer, blocking agent, isolating agent, washing buffer|
First prepare the sample to be tested and the standard. Dilute the sample appropriately using dilution buffer. Select the assay range to design the concentration of the standard solution and perform a gradient dilution.
First, absorb the antibody onto the surface of the solid phase carrier to make a capture agent. The commonly used solid phase carriers are polystyrene, which can be made into microtubes, discs and microspheres. The specific style is designed according to the needs of the experiment. Then incubate the capture antibody with the sample. The antigen in the sample reacts immunologically with the antibody on the solid phase carrier.
Add radioisotope-labeled antibody and incubate. Since the antigen has multiple binding sites, it can bind to the labeled antibody and eventually form an antibody-antigen-labeled antibody immune complex on the surface of the solid phase carrier. Finally, wash with buffer to remove the free labeled antibodies.
Determine the count rate of radioactivity carried by the solid phase. Plot the curve according to the standards and calculate the sample antigen concentration.
You can refer to our IRMA protocols and troubleshooting for your measurements. As well as our IRMA services include custom radiolabeling services. If you are interested in our services, please contact us.
For research use only. Not intended for any clinical use.