The use of a bacterial expression system allowed the production and purification of PDX1 for <I>in vitro</I> phosphorylation analysis. This procedure allowed the purification of several forms of PDX1, some of which have never been reported previously. This study reiterates the fact that the activation of PDX1 and insulin gene transcription arises by a complex series of events, which are rapidly being unravelled, to provide greater insight as to how to obtain gene therapy treatments for diabetes mellitus.