Abstract：Aim To obtain Fab antibodies against Clonorchis sinensis CAg Methods Cs MAg was used in panning from phage library against Clonorchis sinensis The MAg binding activity and specificity of phage antibodies were assayed by ELISA Results 206 random clones were tested for the presence of anti Cs MAg Fabs,and 23 clones showed positive The specificity of these 23 clones was confirmed by binding them to other four trematode antigens(Paragonimus westermani,Fasciola hepatica,Fasciolopsis buski,Schistosoma japonicum) There were 3 clones(B05,C10,E38) bound to Cs MAg but not to any of the other four trematode antigens Comparison of the Fd gene and light chain gene of E38 and B05 with GenBank and KABAT database showed that the heavy chains belonged to human IgG1 subclass,and their variable regions were derived from rearranged germ line gene of V HⅠ 69,D3 10 and J H3 while the light chains were a member of VκⅠ family,the germ line genes were V κⅠ(O2) and J κ1 Conclusions Phage Fab antibodies against Clonorchis sinensis CAg are selected from antibody library It also suggests that the phage antibody library is constructed successfully
