Patent ID: 8735156

Claim:
A composition comprising an isolated rat spermatogonial stem cell and spermatogonial stem cells expanded therefrom and a culture medium, wherein the culture medium comprises: 1:1 ratio of Dulbecco's Modified Eagle Medium (DMEM) to Ham's F12 nutrient mixture, from about 10 ng/ml to about 30 ng/ml glial cell-derived neurotrophic factor (GDNF), from about 10 ng/ml to about 30 ng/ml Fibroblast Growth Factor-2 (FGF2), from about 50 to about 120 μM 2-mercaptoethanol, from about 3 mM to about 10 mM L-glutamine, and a 1× concentration of B27 minus vitamin A supplement solution.