Rapid food safety test LSY-20053

for milkimmunochromatographic

The Nitrofuran(SEM) rapid test dipstick is based on competitive inhibition immuno-chromatographic principle. In the flow process, Nitrofuran(SEM) in the sample combined with Nitrofuran(SEM) specific colloidal gold-labeled monoclonal antibody, Inhibit the combination between antibody and Nitrofuran(SEM)-BSA conjugate on Test line of NC membrane, lead to the color change of Test line. When the sample has no Nitrofuran(SEM) residue or concentration lower than detection limit, T line is darker than C line or T line has same color with C line; when the concentration is equal to or higher than detection limit, T line is obviously lighter than C line or T line has no color. No matter whether there is Nitrofuran(SEM) residue in sample, C line will appear, it means the test is valid. 6. Sample preparation 6.1 Solution preparation 0.1MK2HPO4 solution: Dilute1M K2HPO4 solution with deionized water at 1:9. 6.2 Sample treatment Fresh milk: 1) Take 3ml mixed fresh milk sample into 50ml centrifuge tube, add 6ml deionized water、1.5ml 1M HCl and 300ul Derivatization reagent, shake and mix for 2min, put at 60℃water bath for 30min; 2) Add 7.5ml 0.1M K2HPO4 solution、2.4ml 1M NaOH shake and mix for 1min, add 10ml ethyl acetate, shake and mix for 1min, centrifuge at 4000r/min for 10min; 3) Take 5ml up-layer liquid into glass tube, blow to dry at 56℃by Nitrogen or air.(Dryis OK,do not keep blowing for a long time afterdry to avoidaffectingthe sensitivity) 4) Add 2ml n-hexane shake for 30s to dissolve the dry residue (if do not dissolve the residue completely, it may lead to the result unstable),