Liposome immunoassay (LIA) with antigen-coupled liposomes containing alkaline phosphatase.
Immunoliposomes were prepared and their immunoassay applications investigated. Liposomes were prepared from cholesterol and phospholipids including maleimidobenzoylphosphatidylethanolamine (MBPE) for conjunction with thiol-containing antigens. Alkaline phosphatase (APase) was entrapped in the liposome and BSA, the antigen, was modified by reaction with 3-(2-pyridyl-dithio)propionyl N-hydroxysuccinimide ester (SPDP) to introduce thiol groups for efficient coupling. BSA-coupled liposomes (immunoliposomes) were incubated with anti-BSA serum, complement, and then with APase substrate. The amount of coupled BSA was affected by the reaction time, the composition of the liposome and the BSA concentration in the reactant. The amount of enzyme released from immunoliposomes as a final result of the immunoreaction increased with increasing concentrations of complement and antibody. The liposome immunoassay offers a relatively rapid and simple testing procedure to quantitatively or qualitatively determine the presence or absence of antibodies, or antigenic materials for diagnostic purposes.
Kim
C K
CK
College of Pharmacy, Seoul National University, San 56-1, Shinlim-dong, Kwanak-gu, Seoul 151-742, South Korea.
Lim
S J
SJ
D000469:Alkaline Phosphatase; D000818:Animals; D002784:Cholesterol / Q000032:analysis; D003165:Complement System Proteins / Q000276:immunology; D007106:Immune Sera / Q000276:immunology; D007118:Immunoassay / Q000379:methods*; D008081:Liposomes; D011817:Rabbits
D007106:Immune Sera; D008081:Liposomes; D003165:Complement System Proteins; D002784:Cholesterol; D000469:Alkaline Phosphatase