title: Liposome immunoblotting assay using a substrate-forming precipitate inside immunoliposomes.
abstract: A new immunoblotting assay which uses antibody-coupled liposomes containing horseradish peroxidase is proposed. A substrate 4-chloro-1-naphthol permeated through the phospholipid membrane of the antibody-coupled liposomes and formed a colored product precipitating inside the liposomes. The precipitates accumulated in the liposomes and could be detected at the positions where the liposomes coupled with a target in blotted samples. Combination of liposomes with average diameter of 350 nm and a PVDF membrane with a pore size of 450 nm, 0.02 ng of IgM was detected, while the conventional immunoblotting using antibody-HRP conjugates detected 2 ng of IgM. The sensitivity increased about two orders of magnitude by the liposome immunoblotting assay. This liposome immunoblotting assay gives a simple detection method of proteins with a high sensitivity, as well as a high sensitivity Western blotting assay.
mesh_terms: D015153:Blotting, Western / Q000379:methods; D011232:Chemical Precipitation; D002919:Chymotrypsinogen / Q000032:analysis; D006735:Horseradish Peroxidase / Q000276:immunology; D015151:Immunoblotting / Q000379:methods*; D008081:Liposomes / Q000276:immunology*; D008567:Membranes, Artificial; D010316:Particle Size; D010539:Permeability; D016062:Porosity; D013379:Substrate Specificity
chemical_list: D008081:Liposomes; D008567:Membranes, Artificial; D002919:Chymotrypsinogen; D006735:Horseradish Peroxidase