Over the last few years automation has had a profound impact on the performance of routine immunoassays in the clinical laboratory, Although the automation of specialized, labor-intensive methods has been driven largely by economic pressures, the development of several new technologies have made automation feasible, One of the most significant contributions has been the use of non-isotopic immunometric assays, which have made it possible to carry out sensitive measurements of circulating peptides within minutes, as compared to days with conventional radioimmunoassays, The use of excess reagents in shortened reactions does impose a requirement for careful design of these procedures, in particular with regard to antibody crossreactivities. Nevertheless, the ability to perform STAT measurements for urgently required substances such as cardiac markers provides significant benefits in clinical management, in addition to the improvements in laboratory economy resulting from automation.