Development of the human dispermic embryo

In a recent CD-ROM, we portrayed the microstructure of the pre-implantation human embryo (Sathananthan et al., 1999), which was a multimedia productio n with computer colour-enhanced electron micrographs of mainly monospermic embryos. This disk portrays light and electron micrographs of over 250 trip ronuclear (3PN), dispermic, human embryos during pre-implantation developme nt, viewed in thick and thin Araldite sections, as well as appearances of w hole embryos flat embedded in Araldite blocks visualized with the light mic roscope, The 100 figures were computerized (TBM TIFF format), edited and la belled using Adobe Photoshop 5, Some of the figures were coloured on comput er. The early development of 3PN embryos overtly resembles that of normal e mbryos but there are important differences in their microstructure which ar e portrayed in this presentation. This is a multicentric study involving re searchers from four IVF centres.