Hi guys, I have cultured stem cells isolated from murine adipose tissue recently, it's is cultured in medium including 15% Gibco fetal bovine serum, 94% DMEM low glucose medium, and 1% Penicillin-streptomycin, but unfortunately the stem cells get aging, it's proliferation gets slower than before at 15th day and its' outlook change in Flattened polygonal. So, should I raise the percent of fetal bovine serum? OR adding any growth factor? Or other measures should be taken in culture? Thanks for your advice or experience shared.