A radioimmunoassay for methotrexate adapted to the Centria System 2.

An automated radioimmunoassay for methotrexate using an iodinated tracer has been applied to the centrifugal analyser, Centria System 2. Results obtained for serum samples correlated closely with those using a manual radioimmunoassay method. A major advantage of the assay is its potential for processing large numbers of samples rapidly, making it highly suitable for routine clinical use.