Organophosphorus agents are organic compounds containing a phosphorus atom as the central element.
Some of these compounds are used as chemical weapons.
These compounds attach to the active site of acetylcholinesterase.
Enzyme and inhibit it?s function. One of these compounds which has been extensively used against Islamic combatants as will as Iranian civilians by the Ira qiregim is tabun.
Tabun is a small molecule which itself is unable to activate the immune system. Therefore, it has to be conjugated with a carrier which has a higher molecular weight. Tabun is conjugated with egg albumin, bovin serum albumin (BSA) and key hole limped hemocyanine. Different methods including direct and indirect, using different pH and buffers were employed to conjugated tabun to protein.
The resulting conjugated were purified and identified through quantitative and qualitative analysis.
The Subsequent stage was to immunize rabbits.
Animals were divided in four groups, The first group was injected with tabun-BSA conjugate, The second was injected with BSA, the third was injected with tabun conjugated with KLH, and the fourth was injected with KLH only. The program of immunization for each group consisted of four injections in the first, second, third and fourth months and blood was collected two weeks after each injection. Antibody were qualitatively evaluated using two Techniques. First, The diffusion Test in gel was employed, which showed a positive precipitation line against BSA, Tabun- BSA conjugated and tabun conjugated with egg albumin. No precipitation line was formed against the egg albumin alone. The second method was, conter immunoelectrophoresis, in which a positive precipitation line against tabun conjugated with KLH was obtained, while no precipitation line appeared against KLH alone.
Titration of antibody was evaluated by the conter immunoelectrophoresis Technique.
Serum containing antibody against tabun was injected to mice (Suri) and subsequently a lethal dose of tabun was administered to the animals.
The time that the animals lived following contamination was recorded and compared with controls. Results suggest that the specific antibody prepared against tabun significantly delays the death of the animal.