Staining of several embryos from 2 couples (1 & 2) with either nonimmune IgG (1A and 2A) or TRP53 antibody (all other embryos). Two images of each embryo (except 2C) are provided: an equatorial confocal section (confocal) or phase contrast (phase). All confocal images were taken with identical microscope, laser and magnification settings. The position of the inner cell mass is identified by a white arrow where applicable. The bar is 10 μm, N.A. is not available.