Purpose: Enzyme-linked immunosorbent assays (ELISAs) were developed to screen for sulfonamides and tetracyclines in animal tissues. Performance was validated according to 2002/657/EC guidelines and results were reported.
Methods: Following 2002/657/EC guidelines for screening assays, validation for sulfonamide screening was completed by collecting ELISA data on extracts from 60 different bovine kidney samples spiked with 100 ppb sulfadimethoxine and 60 negative controls. Use for avian muscle was then validated by collecting ELISA results for extracts from 20 different avian muscle samples spiked with 100 ppb sulfadimethoxine and 20 negative controls. Similarly, validation of the extraction and ELISA for tetracyclines was completed in porcine and avian muscle tissue.
Results: Mean ELISA results were 71.3 ± 37.5 ppb for 100 ppb sulfadimethoxine spiked kidney samples, 2.2 ± 2.6 ppb for unspiked, 81.5 ± 25.6 ppb for spiked avian muscle samples and 1.0 ± 1.0 ppb for unspiked avian samples. Two of the 60 sulfa spiked kidney samples and none of the spiked avian muscle samples were false compliant. Mean ELISA results were 9.9 ± 2.3 ppb for 10.0 ppb tetracycline spiked porcine muscle samples, 0.2 ± 0.9 ppb for unspiked, 6.7 ± 2.0 ppb for spiked avian muscle samples and 0.01 ± 0.04 ppb for unspiked samples. Three of the 60 tetracycline spiked porcine muscle samples and none of the tetracycline spiked avian muscle samples were false compliant. All data sets conformed to 2002/657/EC criteria for screening methods.
Significance: To help ensure animal protein products are not contaminated with drug residues, validated ELISA screening methods are now available for detection of sulfonamide and tetracycline in animal tissues.