Pengaruh berbagai konsentrasi etilen glikol dan dimetil sulfoksida dalam vitrifikasi terhadap perkembangan kultur blastokista awal mencit (mus musculus l.) galur DDY hasil laser assisted hatching = The effect of different concentrations of ethylene glycol and dimethyl sulfoxide in vitrification of earlycy blastocyst culture of mice (mus m blastousculus l.) strain DDY after laser assisted hatching