Study On The GICA Strip For Tetracycline Drugs In Aquatic Products

Tetracyclines mainly include tetracycline, oxytetracycline and chlortetracycline. They are widely used in various fields because they have a good bactericidal effect at higher concentrations. As a result of this, they are abused. They have a serious threat to humans and the environment for that they can cause allergic reactions and other diseases in humans. However, the detection methods for tetracyclines we use now are so complicated. In order to quickly detect tetracyclines, we need other methods.The method of GICA strip has been widely used in many fields since it was discoveried because it is fast and efficient, safe and convenient. The study aims to develop and optimize the preparation conditions to obtain high quality immunochromatographic strip.In this study, we use sodium citrate reduction to made colloidal gold solution and determine the optimum conditions by studying on the factors which influence the preparation. In the condition of adding chloroauric acid solution firstly, then 0.5 m L 4%trisodium citrate solution and at a speed of the second speed, a heating time of 10 min, we prepared the 20 nm colloidal gold solution we needed.Before carrying out colloidal antibody, we made a spectral scanning for colloidal gold with the UV-visible spectrophotometer to identify the quality. By studying the factors of gold-labeled,we prepared the gold-labeled antibody under the conditions of adding 9.6 μg antibody, in p H 8.0, 6-fold dilution of the antibody and 30 min of marked time.By studying the factors such as NC membrane, the ionic strength of coating solution, coated Concentration, and the treatment of conjugate pad, we prepared the tetracyclines immune colloidal gold strip under the condition of using using Millipore 135 membrane of NC, 8.5 g/L of the ionic strength, 1.0 mg/m L of the test line coating concentration, 0.75 mg/m L of the control line. And we identify the quality of the test strip through the study of the test strip and the sensitivity, specificity, stability, repeatability.Using the the strip we prepared,the positive samples which include 20 ng/m L of tetracycline, 20 ng/m L of oxytetracycline, 25 ng/m L of chlortetracycline can be detected quickly. In the actual detection of shrimp, the sensitivity of the test strip up to 80 μg/kg.