Monoclonal antibodies - prospects and applications

Abstract

It is becoming increasingly important to screen for marine pathogens, using diagnostic tests which are both reliable, quick and inexpensive. Conventional procedures of isolating and characterizing micro-organisms are both time consuming and expensive. It is to be stressed that diagnostic tests for detection of fish pathogen and also for spoilage causing organisms, should be rapid, simple and reliable. Serology has to a great extent simplified monitoring and detection procedures of most pathogenic micro-organisms. Serological tests are now being used on a routine basis for disease diagnosis all over the world, both for human beings and for animals. Conventional serological tests however used polyclonal antisera, which has very little avidity pertaining to immunoglobulin binding. In other words the specific antibodies represent a diverse spectrum of molecules with different avidities (binding capacities), directed against different epitopes of the antigen. This could lead to several problems viz; cross reactivity, less specificity, batch to batch variation in results etc. The technique of monoclonal antibodies has revolutionized several areas of modern biological research. Monoclonal antibodies are finding increasing use in disease diagnosis and pathogen detection. They are produced by immortal clones of cells called 'Hybridomas'. They are identical with respect to several useful parameters viz; IgG subclass, allotype, variable regions, structure, idiotype, affinity and specificity for a given epitope. In using a polyclonal antiserum, the binding of non-specific IgG relative to antigen specific IgG may be uncomfortably high. This problem is greatly reduced with a monoclonal antibody leading to a much higher signal to noise ratio. A monoclonal antibody is capable of being applied in a variety of serological tests.