Immunoassay analysis of lysergic acid diethylamide.

Screening large numbers of urine samples for drugs of abuse is typically accomplished using immunoassays that allow for processing large numbers of samples without the requirement of sample preparation before analysis. Until fairly recently, screening of lysergic acid diethylamide (LSD) in urine samples could only be accomplished by the use of radioimmunoassays (RIA). Recently, new nonisotopic immunoassays have been developed for the screening of samples for LSD. These assays lend themselves to rapid, high-volume, automated analysis compared with RIA procedures. In order to evaluate the current commercially available assays, samples prepared at known concentrations were tested by each of the assays. In addition, samples from known use of LSD were tested and the performance of each of the assays compared. The assays examined in this study included RIA assays from Roche Diagnostics (Abuscreen) and Diagnostic Products (coat-a-count) and nonisotopic assays from Roche (OnLine), Behring (EMIT), Boehringer Mannheim (CEDIA), and STC (Microplate EIA). Assays that could readily be carried out in a semiquantitative mode (determining concentration based on a calibration curve) were evaluated as to their relative response to the samples tested. All of the assays evaluated identified all of the samples which confirmed positive by gas chromatography-mass spectrometry (GC-MS). Likewise, each of the assays identified some samples which did not confirm as positive by GC-MS.