Neutralization Tests

Neutralization tests are performed in vitro , at the cellular level - including on cells in the form of organs - and at the sub-cellular level. They assess the efficacy of antibody fragments, or antibodies, to inhibit critical stages of activities. These activities are generally deleterious to Humans, and neutralization tests mostly apply to viruses and toxins. When isolating recombinant antibodies, in vitro tests are particularly important because these antibodies are generally isolated first in the form of antibody fragments, which have too short a half life to allow in vivo assessment. Here, examples of toxin neutralization tests at the cellular (ricin), sub-cellular (light chain of botulinum toxins) and at the organ level (heavy chain of botulinum toxins) will be described. A plaque reduction neutralization assay (dengue) will also be presented and guidelines about other virus neutralization tests will be exposed. Generally, this chapter is an introduction to the critical screening tests utilized when searching for neutralizing antibody fragments.