Validation of the LacTek test applied to spiked extracts of tissue samples: Determination of performance characteristics

LacTek(TM) tests ape competitive enzyme-linked immunosorbent assays intende d for rapid detection of antimicrobial residues in bovine milk. In this stu dy, the LacTek test protocol was modified for use with extracts of bovine t issue to detect P-lactam, tetracycline, and sulfamethazine residues. Test p erformance characteristics-precision, accuracy, ruggedness, practicability, and analytical specificity and sensitivity-were investigated. Results sugg est that LacTek tests can be easily adapted to detect antimicrobial residue s in extracts of lean ground beef. However, positive samples may not contai n residues at violative concentrations (i.e., Canadian maximum residue limi ts), and therefore, additional analysis would be required for final confirm ation and quantitation (e.g., chromatography).