ELISA: highlights of the present state of the art.

ELISA is now very widely used. Many variations on the theme have been described. The search for further improvements is ongoing, mainly in the areas of sensitivity, specificity and practicability. Of course, the application of monoclonal antibodies is important in this respect. Next to that, further improvements in the detection of the enzyme label have come to the fore. Examples regarding the use of tetra-methylbenzidine as a peroxidase-substrate and details on its safety, a novel amplification method for detecting alkaline phosphatase and an enhanced luminescence method to detect peroxidase are given.