Aflatoxin B 1 : Specific Antibodies and Their Use in Radioimmunoassay 2 3

Abstract

New Zealand White rabbits immunized with covalent conjugates prepared from polylysine and the O-carboxy-methyloxime derivatives of either aflatoxin B1 (AFB1) or an analogue, 5,7-dimethoxycyclopentenon (2,3-c) coumarin, produced antibodies that bind 3H-AFB1. The specificities of the antisera with respect to aflatoxins BI, B2a, G1, G2, Q1, P1, and some other structually related compounds were determined. Radioimmunoassays that can detect levels as low as 0.27 pmoles (0.06 ng) of AFB1-were used to analyze serum, urine, and crude extracts of corn and peanut supplemented with aflatoxin. In the foodstuffs, as little as 1 mug AFB1/kg was measured. The immunoassay was at least as sensitive and specific as other available analytic methods, but did not require the purification of samples by chromatography before analysis. The technique may be particularly useful in epidemiologic studies designed to study the possible relationship between chronic aflatoxin ingestion and cancer.

A monoclonal antibody to aflatoxin B1: detection of the mycotoxin by enzyme immunoassay

“…These methods are time consuming, labour intensive and costly. More recently, immunoassays developed for the Langone & Van Vunakis 1976). The use of antibodies specific for AFB,, reduces assay time and sample preparation, increases sensitivity and potential for large scale screening suggests that immunoassays will be of particular use in AFB, determination.…”

“…The production and characterization of this monoclonal antibody and details of an ELISA procedure to detect accurately the levels of AFB, in foods are described. AFB, has no reactive groups for coupling reactions so the AFB,-1-(0-carboxymethyl) oxime (AFB ,-oxime) derivative was first prepared by combining two previously published methods (Chu et al 1877;Langone & Van Vunakis 1976). AFB,-oxime was then coupled to the desired protein in the presence of the water soluble carbodiimide, EDPC, as described by Chu & Ueno (1977).…”

Advances in hapten immunoassays

“…These include the antimetabolite methotrexate (75,76), the cytostatic active antibiotics adriamycin and daunomycin (77) and bleomycin (78), the organochlorine insecticides aldrin and dieldrin (79), the irreversible cholinesterase blocker parathion (80), the carcinogen aflatoxin 81 (81), the toxins of the dangerous toadstool Amanita phalloides, amanitins (42,82), the tuberculostatic drug isoniacid (83), the cardiovascular drugs 9,1O-dihydroergotamine (84), saralasin (85) and theophyllin (86), the peptide hormones motilin (87) and substance P (88), the anti-ulcer drug carbenoxolone (73), the polyamine spermine (36), several prostaglandins and prostaglandin metabolites (89,90,91,92), thromboxane 82 (93), the opiate antagonist naloxone (94), the benzodiazepine chlordiazepoxide (95), colchicine (96,97), a drug used in gouty arthritis, the pineal hormone melatonin (98,99) and (j-3,4-dimethoxyphenethylamine (100), a compound possibly associated with certain mental diseases.…”

Production and characterization of aflatoxin B2a antiserum

“…The ubiquitous nature of this toxin and its related metabolites requires a rapid and sensitive means for monitoring their presence in the food supply and in animal tissues. During the past 5 years there has been considerable interest in the development of quantitative immunoassays for afla B1 (8,13,14,15,21). Two basic approaches for eliciting antiserum specific for afla B1 have been devised.…”

“…In the first method, afla B1 is converted to afla Bl-O-carboxymethyloxime (7) and then conjugated to bovine serum albumin (BSA) to yield an effective immunogen. Antibody generated in this manner (afla B1 oxime antiserum) has been used in the radioimmunoassay (RIA) and enzymelinked immunosorbent assay (ELISA) of afla Bl, and its specificity has been well characterized (8,13,15,21). In the second approach, afla B1 is chemically converted to afla B2.…”