Enzyme immunoassays have become solidly entrenched in many fields. Unfortunately, they are often performed in a haphazard way. This is not altogether surprising since this powerful assay technology transcends several discipline boundaries and is extensively applied as a tool in fields other than enzymology and immunology. The fast flow of new ideas and assay designs and the rapid progress in the application of this technique may be reasons why comprehensive reviews on this subject are still missing.

It is attempted in this book to provide both the basic understanding of these techniques and a practical guideline for the choice and experimental details of enzyme immunoassays. Another goal of this review has been to be sufficiently provocative to leave the very diverse group of veteran or would-be assayists (clinicians, applied and basic scientists) with a healthy distrust of the, frequently misleading, accepted wisdom abounding in EIA-logy. I hope that this effort will be useful since researchers in the life sciences are frequently concerned with the detection or discrimination of minute amounts of resembling compounds, not seldom at the limit of detectability.

Intricate interactions among different assay parameters (sensitivity, detectability, specificity, etc.) and differences in their concepts have been emphasized and uniformly used throughout the text to avoid the confusion reigning in the literature. This attempt to prevent confusion necessitated the introduction of a few new terms, which I hope, will be inoffensive.