Transcription Factors are proteins that affect the expression of genes. Embryonic genome activation is the time in mammalian development when the embryo's genome gets transcribed for the first time. Transcription factors such as Dux4 play a role in activating the embryonic genome. The lab recently discovered a new candidate transcription factor, Rhox12u, which is expressed during embryonic genome activation in mice. To further study the roles of Rhox12u and Dux4 we purified the transcription factors from E.coli.