Definitive endoderm derived from culturing human embryonic stem cells (HUES4) with Inhibin beta a (ab50051) and Wnt3a (ab81484) was further differentiated to primitive gut tube as described in Kroon et al, Nat Biotechnol. (2008). KGF (ab9601) was added to the media to direct differentiation towards primitive gut tube. These images were taken 3 days after addition of KGF, where the primitive gut tube marker TCF2 (ab59118 in green) is present. Dapi staining is shown in blue. Magnification of top panels: 100x, bottom panels: 200x. Negative controls of fluorescently conjugated secondary antibodies only, showed no staining. For more information on this immunofluorescence, please see abreview.See Abreview