Radioimmunoassay of lysergic acid diethylamide (LSD) in serum and urine by using antisera of different specificities.
W A Ratcliffe, S.m. Fletcher, A.c. Moffat, J. G. Ratcliffe, W. A. Harland, T. Levitt
Clinical Chemistry February 1, 1977 DOI: 10.1093/clinchem/23.2.169 via OpenAlex
Summary
AI-generated from the abstractHigh-titre antisera were raised to two LSD-bovine serum albumin conjugates, each specific for different parts of the LSD molecule. These antisera enabled a double-antibody radioimmunoassay with a detection limit of about 0.4 micrograms of LSD per liter of unextracted urine or serum, with no nonspecific interference from urine, serum, or common drugs. Immunoassay values from the two antisera correlated well (r = 0.91), though the antiserum linked via the indole nitrogen gave consistently higher results for samples from people who had taken LSD due to greater cross-reactivity with LSD metabolites. Using two such antisera provides a more specific screening procedure for LSD abuse and allows measurement of metabolites for which no satisfactory method previously existed.
Study at a glance
| Characteristics | Experimental study Peer reviewed |
|---|---|
| Topics | LSD |
| Keywords | Radioimmunoassay Urine Antiserum Immune sera |
| Citations | 38 |
| Key finding | A double-antibody radioimmunoassay using two antisera specific for different parts of the LSD molecule can detect about 0.4 micrograms of LSD per liter of unextracted urine or serum and provides a more specific screening procedure for LSD abuse. |
Abstract
Abstract We raised high-titre antisera to two LSD-bovine serum albumin conjugates, one linked via the indole nitrogen, the other via the amide side-chain. The antisera were specific for different parts of the LSD molecule, as demonstrated by cross-reactivity studies with LSD, its metabolites, ergot alkoloids, and closely related compounds. The antisera were used to develop a double-antibody radioimmunoassay with a detection limit of about 0.4 mug of LSD per liter of unextracted urine or serum. We saw no nonspecific interference by urine, serum, or from a series of commonly used drugs. There was good correlation between immunoassay values obtained with the two antisera (r = 0.91). However, the antiserum linked via the indole nitrogen gave consistently higher results for samples from persons who had taken LSD, owing to greater cross-reactivity with LSD metabolites. Radioimmunoassay by use of two such antisera is a more specific screening procedure for LSD abuse than has been available previously. In addition, antisera cross-reacting with LSD metabolites allow measurement of these compounds, for which there is no satisfactory method at the concentrations found in biological fluids in man.