TerELISA: the ELISA test performed in Terasaki plates

The use of Terasaki (10 microliter samples) and microtitration (100 microliter samples) plates as the solid phase in enzyme immunoassays was compared. Various antigens were used for coating the plates and antibodies present in human sera were evaluated using the same anti-human Ig antibody labelled with either beta -galactosidase, alkaline phosphatase, peroxidase or glucose oxidase. The results obtained, either by scoring with the naked eye or by absorbance reading with appropriate densitometers, showed that both plates were equally suitable and that the 4 enzymes were equally effective in detecting the same lowest quantity of antibody. A comparative evaluation using either Terasaki or microtitration plates for the quantitation of human anti-Echinococcus granulosus antibody ii 50 sera demonstrated that there was a good correlation between the two procedures (r = 0.8097). Finally, the use of glucose oxidase as the enzyme marked allowed a clear-cut distinction to be made between positive and negative samples with the naked eye alone.