Abstract: Isogenic C57BL/6 female mice at 6~7 weeks of age were inoculated with male spleen cells from the same strain. RNA was isolated from immunized female mice spleen cells using TRIZOL method. The first-strand cDNA was reverse transcribed from total RNA using an oligo(dT)18 primer, the κ light-chain and the Fd (Vh-Ch1) regions of heavy-chain products were amplified from the cDNA template by polymerase chain reaction (PCR) with specific primers. To generate the pComb3-κ and pComb3-κ-Fd library, κ light chain and Fd gene fragments were inserted into phagemid vector pComb3 respectively, then transformed into E. coli strain of XL1-Blue competent cells, the transformants were plated for a blue-white color screening. The recombination rates of κ light chains and Fd fragments were 80％which was confirmed by PCR and endonuclease digestions. A mouse combinatorial Fab library was constructed by the help phage
VCSM13 infection, which gave 1.5×107 colonies with the titer of 3.2×1011 pfu/ml. The presence of mouse Fab on the phage surface was determined by ELISA. 9 of 18 strains had specific binding capacity to male spleen cells，8 of 18 strains had specific binding capacity to testicle cells. The mouse Fab antibody library could be used for selection of H-Y antigen binding Fab phage. These new molecules are potentially valuable tools in the study for molecular characteristics and functional analysis of H-Y antigen and antibody, the application of embryo sexing in mammals.