Abstract:

A simple and rapid method based on colloidal gold immunochromatography for the detection of
neomycin residues in milk was established. Two different concentrations of complete antigen for artificially synthetic
neomycin were coated onto a nitrocellulose membrane as the test lines (T1, T2), which could compete the binding between
neomycin monoclonal antibody coating colloidal gold and the free neomycin in milk samples. In this way, the accuracy of
traditional neomycin colloidal gold test strip was improved from qualitative to semi-quantitative detection by the color of
T1 and T2 lines. The semi-quantitative detection limits of the test lines T1 and T2 for milk samples were 200 and 400 μg/kg,
respectively, which could meet the requirement of the EU and the national standard for the determination of the maximum
residue limit (MRL) of neomycin. Also, this test strip enabled rapid on-site detection of neomycin residues in milk samples.

Key words: neomycin, semi-quantitative test, colloidal gold, complete antigen, field test, rapid detection