OTC (Oxytetracycline) ELISA Kit

Built around a competitive immunoassay format, this Assay Genie oxytetracycline kit quantifies OTC residues across heterogeneous food matrices including meat, raw milk, eggs, and animal feed. The assay reports a sensitivity of 0.3 ppb (ng/mL) and reaches detection limits of 6 ppb for meat, milk, and egg samples versus 400 ppb for feed, providing laboratories with a quantitative screening window suited to veterinary drug residue monitoring programs. Cross-reactivity profiling demonstrates 100% recognition of oxytetracycline, 300% with chlortetracycline, 206% with tetracycline, and 18.5% with doxycycline, giving analysts useful context for interpreting tetracycline-class carryover in tested commodities.

The workflow uses an antibody-coated 96-well microplate read on a microplate reader at 450 nm with a 630 nm reference, with incubations carried out at 25°C for approximately 30 min followed by 15 min. Six liquid standards (0, 0.3, 0.9, 2.7, 8.1, and 24.3 ppb) support curve construction, while the supplied HRP conjugate, substrate A and B, stop solution, and 20× concentrated wash buffer and sample diluent cover the full reaction sequence. Sample preparation relies on trichloroacetic acid extraction and ZnSO4-based clean-up, requiring a homogenizer, centrifuge, balance, and single- or multi-channel micropipettors (20-200 µL, 100-1000 µL, and 300 µL).

Intended for research use only, the kit is suited to food safety laboratories, dairy processors, regulatory testing services, and academic researchers evaluating veterinary antibiotic carryover, where it functions as a high-throughput screen ahead of instrumental confirmation by LC-MS/MS. Components should be handled refrigerated, stored at 2-8°C, and protected from freeze-thaw cycles to preserve antibody binding activity and calibration integrity over the 12-month shelf life.