POLARIZATION FLUOROIMMUNOASSAY OF PROPAZI NE IN REVERSED MICELLES OF AEROSOL OT IN N-OCTANE

The interaction between fluorescein-labeled propazine and antibodies a gainst this hapten was studied in the reversed micelles of Aerosol OT in n-octane by a polarization fluoroassay. The effect of the hydration degree of micelles W-0 (W-0 = [H2O]/[Surf]), which determines their s ize and surfactant concentration, on the binding of the antigen with a ntibodies was studied. A high hydration degree of the reversed micelle s (W-0 = 15-30) and low concentration of the surfactant (less than 50 mM) are optimal for binding. The binding efficacy depends upon the str ucture of the fluorescein-labeled hapten, particularly upon the length of the bridge binding fluorescein with propazine. It was shown that t he polarization fluoroimmunoassay of propazine may be carried out in a reversed micellar system in nonpolar organic solvent (octane) with a detection Emit of about 100 nM (20 mu g/l). This is an order of magnit ude higher than that achievable upon analysis in aqueous medium. The p roposed polarization fluoroimmunoassay in a reversed micellar system m akes it possible to detect haptens that are poorly soluble in water di rectly in organic extracts, e.g., in chloroform solutions.