Development of one-step strip test for detecting chemical compounds with small molecule weight is a very challenging task. Since the detection limit of strip test format is usually one or two orders of magnitude less than ELISA format, the success of assembling strip test is strictly limited by the quality of antibodies, e.g. sensitivity and specificity. Thus, the production of hapten-specific antibodies with high sensitivity and specificity is crucial and a prerequisite for successful assembling of test strips....[ Read more ]

Development of one-step strip test for detecting chemical compounds with small molecule weight is a very challenging task. Since the detection limit of strip test format is usually one or two orders of magnitude less than ELISA format, the success of assembling strip test is strictly limited by the quality of antibodies, e.g. sensitivity and specificity. Thus, the production of hapten-specific antibodies with high sensitivity and specificity is crucial and a prerequisite for successful assembling of test strips.

This project aims at developing ELISA format and strip test that can quickly detect the presence of two antibiotics, i.e. Trimethoprim (TMP) and Enrofloxacin (ENR), in animal body fluid and products. In order to increase the immunogenicity of chemical compounds, different conjugation strategies were used to couple the antibiotics, TMP and ENR to carrier proteins, followed by a comprehensive screening by using different immunogens to immunize animals to produce highly sensitive and specific antibodies against free TMPs or ENRs.

In this project, prototype one-step strip test and indirect competitive ELISA format for detection of TMP was developed by using anti-TMP polyclonal antibodies. Under the most optimized condition, the detection limit for one-step strip test and for indirect competitive ELISA format can reach up to 0.25 μg/ml and 10 ng/ml, respectively. In addition, anti-ENR polyclonal antibodies were also produced. Indirect and direct competitive ELISA formats for detection of ENR were developed by using anti-ENR polyclonal antibodies. The preliminary data showed the detection limit of both formats was less than 1 ng/ml. The successful production of one prototype strip test and ELISA formats will provide the technical rout to further produce commercial products for the rapid detection of TMP and ENR residues in animal body fluid and food animal products.