LIPOSOME IMMUNOASSAY USING A SPIN-LABEL, TEMPO CHOLINE YL)]AMMONIUM-2,2,6,6-TETRAMETHYLPIPERIDINE-1-OXYL) - A NEW STRATEGY FOR DETECTING THIS SPIN-LABEL USING AN ION-SELECTIVE ELECTRODE IN-PLACE OF ELECTRON-SPIN-RESONANCE (ESR)

We devised a new method for detecting the spin label, TEMPO choline l) ]ammonium-2,2,6,6-tetramethylpiperidine-1-oxyl), which is usually appl ied in liposome immunoassay, using a TEMPO choline-selective electrode instead of the conventional electron spin resonance (ESR) method. TEM PO choline was enclosed in the inner aqueous phase of liposomes, and t he release of TEMPO choline from liposomes induced by the complement-m ediated immune lysis reaction was monitored by this electrode. The pot entiometric method using the TEMPO choline electrode was more effectiv e for monitoring the immunoreaction and more economical than ESR metho d.