AUTOMATED LIPOSOME-BASED FLOW INJECTION IMMUNOASSAY SYSTEM

Abstract

A liposome-based flow injection immunoassay (FIIA) system for quantitation ofa clinical analyte, theophylline, and also, with very minor changes in the assay format, of an antibody to theophylline, has been developed. Automated sequential analyses were performed at room temperaturewith picomolesensitivity and a day-to-day coefficient of variation of less than 5 %. The system components include liposomesthat contain fluorophoresin their aqueouscentral cavities and an immobilized-antibody reactor column. The immunoreactor was regenerated hundreds of times over three monthsof continuoususe with no measurable loss of antibody activity. The special advantages ofusing flow injection analysis for immunoassays and ofusing liposomesin FIIA, compared to most current immunoassay techniques,are described.