Collagen IV and laminin granules in human fetal germ cells. Collagen IV (A,C) and laminin (B,D) granules (in green) in the cytoplasm of germ cells (red) in both developing female first trimester (W10.5) and second trimester (W17) gonads. The same secondary antibody was used to detect OCT4 and VASA, both germ cell markers, because the two proteins localize to different cellular compartments (nucleus and cytoplasm, respectively) and their expression can therefore be clearly distinguished. 3D reconstructions from high magnification confocal z-projections from two different angles show that these granules are present throughout the cytoplasm of the germ cells. Scalebar is 2.5 μm.