Summary: The Florfenicol Rapid test kit is based on the specific immuno-chemical reactions between antigen and antibody. It relies on the competition between Florfenicol residues in the sample and the Florfenicol immobilized on T line on the membrane for the Florfenicol antibody-dye conjugate. Since the drug has been presenting in the sample, it will compete with the drug immobilized on T line, to the limited amount of dye-antibody. As a sufficient amount of drug in the sample is presenting, the drug will saturate the antibody. Consequently, it will show an extremely invisible T line, indicating a positive result. On the other hand, if there is a negative sample (or the amount of the residue drug is lower than the minimum detectable concentration), it will generate two obvious lines in both the T and C line section.