Comparison of an Enzyme-Linked Immunosorbent Assay with an Immunochromatographic Assay for Detection of Lincomycin in Milk and Honey

An enzyme-linked immunosorbent assay (ELISA) and an immunochromatographic assay were constructed for the detection of lincomycin (LIN) in both milk and honey samples based on the monoclonal antibody named 5F6. The half-maximum inhibition of ELISA was 0.3 ng/mL after optimizing pH and ionic strength conditions; the limit of detection was 0.07 ng/mL. The cross-reactivity with clindamycin was 0.6%. LIN recovery in spiked milk and honey samples ranged from 84.6% to 115.6% with intra-assay coefficient variations of 1.7-25.4% and inter-assay coefficient variations of 2.7-8.9%. The detection limits were estimated as 2.1 mg/L for milk and 2.1 mg/kg for honey samples. The immunochromatographic assay revealed a LIN cut-off value of 10 ng/mL in PBS, 5 ng/mL in milk, and 120 ng/g in honey, and a visual lower detection limit of 2.5 ng/mL, 1 ng/mL and 30 ng/g in PBS, milk and honey, respectively. The immunochromatographic assay is preferred for large-scale practical application for its simpler pretreatment and satisfied sensitivity compared with ELISA assay.