Purpose: The purpose of this work was to combine the quantification capability and the immunochromatography swiftness into a lateral flow device that detects bovine milk in other species' milk.
Methods: An indicative lateral flow strip consisted of a nitrocellulose membrane with a high affinity monoclonal primary antibody test line and an anti-species control line, a conjugate pad with a colloidal gold conjugated secondary monoclonal antibody and an absorbent pad. Monoclonal antibodies against bovine IgG produced after mice immunisation, preparation of hybridomas, clones screening and protein G purification. The colloidal gold nanoparticles (40nm) were produced by reduction of chloroauric acid and the conjugate with the secondary antibody was carried out by pH-modulated absorption. The milk sample was diluted five times with a running buffer before strip immersion and the percentage of bovine milk was determined by a novel quantification system using a high technology scanning device.
Results: This lateral flow strip requires one drop of milk and the procedure total time is 10 minutes. The combination of the high affinity antibody pair and the advanced quantification system contributed to high range standard curve. According to scanning device findings, the type of graph was close to ELISA method levels.
Significance: This lateral flow device constitutes a very valuable tool in the rapid quantification of cow milk in other species' milk by combining the fast protocol and the significance of the result.