Improved techniques for the rapid radioimmunoassay of ecdysteroids and other metabolites

An RTA procedure for assaying a large number of samples in a relatively short time has been developed. It utilizes multi-channel repeater pipettors for the addition of reagents, specially designed racks which accommodate 48 6x50-mm tubes and which fit directly into the centrifuge, multitube vortexers, and a specially designed aspiration device. The racks allow the tubes to remain in the same support throughout most of the assay. The aspirator permits the rapid aspiration of eight tubes at a time, 192 in 2 min. One hundred ninety-two samples can be accurately assayed in as little as 2.5 h.