Abstract: Objective To analysis the relevance of foreign DNA length to integration efficiency on the randomly gathering data in preparation of transgenic mouse. Methods The statistics analysis was performed on 29 randomly gathered data of generation of transgenic mouse. Result According the regression equation of statistics analysis in this paper, the integration efficiency of foreign DNA was increased with the shorter length of foreign DNA (P<0.001). The foreign DNA fragments integrated into mouse chromosome DNA with 10% efficiency when the length of foreign DNA were less than 6 000 bp. Conclusion There is a negative correlationbetween integration efficiency and foreign DNA length in microinjection.

Key words: Foreign DNA, Transgenic mouse, Integration