OTC (Oxytetracycline) ELISA Kit

Built around a competitive inhibition immunoassay format and calibrated against an in-kit standard curve spanning 0.05 to 4.05 ppb, this Assay Genie kit reaches a sensitivity of 0.05 ppb (ng/mL) and reports matrix-specific detection limits of 0.4 ppb for tissue, liver, and egg homogenates, 0.5 ppb for urine, and 2 ppb for honey. Cross-reactivity profiling shows 100% recognition of both tetracycline and oxytetracycline, 16.7% for chlortetracycline, and 4.2% for deoxytetracycline, consistent with a group-selective tetracycline residue screen rather than an OTC-specific assay.

Each box supplies a strip-format microtiter plate with pre-coated coupled antigen, a 1 mL vial of 1.0 ppm high-concentrated standard, six empty standard bottles used to prepare the 0, 0.05, 0.15, 0.45, 1.35, and 4.05 ppb calibrators, 11 mL of HRP conjugate, 5.5 mL of antibody working solution, 6 mL each of substrate reagent A, substrate reagent B, and stop solution, 40 mL of 20x concentrated wash buffer, 50 mL of 5x reconstitution buffer, three plate sealers, and a sealed foil pouch for unused strips. Sample pretreatment typically involves homogenization, DMF or methanol extraction, centrifugation near 4000 rpm, and dilution with the supplied reconstitution buffer; for honey, a 1 g aliquot is extracted with 2 mL of DMF, while urine is diluted tenfold in reconstitution buffer and clarified by centrifugation.

Validated recoveries fall between roughly 55% and 105%, with reported means of 85% +/- 20% for tissue, liver, and eggs, 75% +/- 20% for honey, and 80% +/- 20% for urine. The reaction proceeds in three timed incubations at 37 degrees C (30 min, 30 min, 15 min), with the colorimetric end-point read on a standard microplate reader and the analyte concentration interpolated from the inverse-absorbance standard curve. The kit is intended for in vitro food-safety screening and veterinary residue monitoring only, and is not cleared for human diagnostic use.