Freely programmable automatic radioimmunoanalysis on the STRATEC ST 300 analyzer

We compared the free programmable automatic radioimmunoassay on analyser STRATEC SR 300 to the manual performance of RIA and IRMA. One-step and two-step methods were evaluated. Manual delivery proved to be faster than the automatic one. The speed of dispensing depends on the volume of the dose sample and of the reagent, on the adjustment of rinsing volumes of the needle, washing volumes among separate doses and also on the size of the sample set. The total efficiency of the manual and the automatic analysis is also affected by other operations, especially by washing test tubes and the administration of reports. For a set of 100 analyses, the manual process is from 20 to 90 minutes longer than the automatic one, depending on the analytical method used. Thus, the automatic analysis proved to be significantly faster. Nor the comparison of isotope and non-isotope immunoassays showed any relevant qualitative or quantitative differences in analytical response. At the same time the prices of radioimmunoassays are more favourable, and in addition to that, a big choice of analytical sets is available which are not dependent on the user's instrumentation. However, this does not concern very small series, or separate tests where size of calibration is important. Moreover, the turn-around-time of RIA and IRMA is in these cases longer than when automatic non-isotope methods are used.