The derivation of mouse embryonic stem cells (ESC) produces mouse embryonic stem cells highly proliferative for using in different studies. Due to their totipotence, since researches “in vitro” of undifferentiating or differentiated cells up to “in vivo” transplants and transgenic animal production make them an useful tool in biologic research. In this work, we aim to use new technologies recently reported in the literature to derivate ESC from important mouse strains maintained at CEMIB/UNICAMP and build a cell bank to researches in the future. We are at the beginning of our work and the results are promising. Despite the culture of primary cells being tricky, everything is working well so far. Many steps require care, but we believe it will be successful. The ESC derivation will lead us to developing new tools for our work.