本文采用我们自己构建的基因工程龋齿疫苗菌株，大罐发酵培养３批、菌体收量平均湿重为２．６７ｇ／Ｌ，表达率为４４．２７％。菌体经超声裂解，硫酸铵和链霉素粗提，再经吸附层检，凝胶过滤和离子交换柱层析等步骤纯化精提ＧＴＦ抗原３批。提纯的ＧＴＦ抗原，平均比活，提纯倍数和收率，分别为５８．３４ｕ／ｍｇ、６．０８倍和１９．２５％。此抗原经ＳＤＳ－ＰＡＧＥ电泳，分子量为５５ＫＤ，纯度达到９６．７％，并对湿度具有较好的稳定性能。且此抗原制备的疫苗免疫家兔具有较好的免疫原性 In this paper, we constructed our own genetic engineering dental caries vaccine strains. Three batches of large pot were cultured. The average wet weight of the cells was 2.67g / L, the expression rate was 44.27%. The bacterial cells were lysed by ultrasonic wave, crudely extracted with ammonium sulfate and streptomycin, and then refined and refined with 3 steps of GTF antigen by steps of adsorption layer chromatography, gel filtration and ion exchange column chromatography. Purified GTF antigen, the average specific activity, purification fold and yield were 58.34u / mg, 6.08 times and 19.25%. The antigen by SDS-PAGE electrophoresis, molecular weight of 55KD, purity of 96.7%, and humidity has good stability. The immunized rabbit prepared by the antigen has good immunogenicity