A Simple Innovative Modification to Enhance the Efficacy of the Complement Fixation Test

摘要

The Complement Fixation Test (CFT) is a serodiagnostic test of high sensitivity commonly used in the diagnosis of infectious diseases like Brucellosis. However, the conventional CFT (cCFT) may sometimes give false negative or false positive result and may lead to incorrect diagnosis. If the results are not read within 30 minutes of finishing the test, it tends to show the signs of negativity making it difficult to find the true results. In the present study, serum samples from Brucellosis affected or healthy cattle were subjected to a modified CFT (mCFT) where, in addition to the regular procedure of the CFT, anti–hemolysin antiglobulin {i.e., [F(ab’)2] of antibody against rabbit IgG}, was added to facilitate the reading of the test. The innovative modification showed a clear hemolysis in negative samples as the antiglobulin binds to the haemolysin leading to pairing of the antibody molecules, enhancing the complement mediated haemolysis. The novel method could help in differentiating the positive and negative samples more explicitly and the test could be read more accurately. In the modified CFT, the results could be recorded easily even after 2 hours of finishing the test, minimizing the chances of wrong diagnosis. The modified CFT with a better readout would enable more accurate serodiagnosis of infectious diseases