Abstract: Hofmann degradation and diazo-reaction of Tetracycline hydrochloride (TCH) happened and conjugated to protein-carrier (BSA, OVA).The conjuagates were synthesized by the means of FeCl3 resolution and UV scanning spectra, and mol conjugation ration of TCH to BSA was 3.2∶1 and TCH to OVA was 4.2∶1.The immunogen(TCH-BSA) was immunized to BALB/c mice and polycolnal antibodies were obtained. Tiler of the antibodies were 1∶51200 by the indirect ELISA and IC^₅₀ was 16.91 ng/mL by the competitive indirect ELISA. It showed that the artificial-synthesized antigen had immunogenicity.

Key words: Tetracycline hydrochloride; Hofmann degradation; diazo-reaction; conjugation; carrier