Immunoassay of pesticides: an update.

Measurement of levels of pesticides residues in foods and crops most often requires extensive cleanup and instrumental techniques such as gas chromatography. Immunoassay measurement techniques, on the other hand, may be used directly on the test portion or require only minimal cleanup. Further refinements of the common antibody-enzyme-based solid-phase assays, such as use of coated magnetic particles, antibody-coated crystals, and continuous-flow devices, have extended the measurement range and applicability of these assays. Likewise, new immunoassays for pesticides have been developed, and existing assays have been refined, optimized, and more completely characterized and validated. In addition to their ability to accurately and reliably measure amounts of residues present in food and crops, immunoassays can be readily used as rapid screening methods for contaminants in field samples. We have previously reviewed much of the work in the area of pesticide immunoassay; this report updates previous information and discusses some new immunoassay techniques.