title: Measurement of C3 conversion by ELISA estimation of neo-determinants on the C3d moiety.
abstract: An ELISA assay estimating neo-determinants on the C3d moiety is described. The C3d neo-determinants were detected by incubating the sample on F(ab')2 anti-C3d-coated plates followed by development with biotin-labelled anti-C3d and enzyme-labelled avidin. The assay was compared with rocket immunoelectrophoresis (IE) and crossed IE. Serum from a factor I deficient patient showed no detectable C3d when analysed by rocket IE, but activation was evident when analysing by crossed IE or ELISA. The results suggest that the neo-determinants detected by ELISA become exposed when C3 is split into C3a and C3b and this interpretation was supported by kinetic analysis of C3 activation by the three methods.
mesh_terms: D003167:Complement Activation; D003176:Complement C3 / Q000032:analysis* / Q000276:immunology / Q000378:metabolism*; D015932:Complement C3c; D015933:Complement C3d; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes / Q000032:analysis*; D006801:Humans; D007700:Kinetics
chemical_list: D003176:Complement C3; D000939:Epitopes; D015932:Complement C3c; D015933:Complement C3d