Radioimmunoassay of lysergic acid diethylamide (LSD) in serum and urine by using antisera of different specificities.
Clinical Chemistry February 1, 1977 W A Ratcliffe, S.m. Fletcher, A.c. Moffat et al. 38 citations
High-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.