Stage 3 specimens have a postfertilization age of between four and five days in vivo. Embryo #8663 is one of two stage 3 embryos in the Carnegie collection. It is a 107-cell blastocyst estimated to be about 108 hours old.

Before fixation the specimen had no zona pellucida and measured 153 x 115 µm. After fixation the overall size of the embryo was 103 x 80µm. ( Table of Dimensions; Hertig et al., 1954)

The specimen was collected and prepared for microscopic examination in 1949. It was fixed in 70% alcohol and Bouin’s fluid, embedded in celloidin paraffin, and serially sectioned at 6 µm. The sections were mounted on a glass slide and stained with H & E. Fifteen serial sections were obtained from the embryo, fourteen of them are included in the database. Structures are identified on every section image. The morphology of this embryo is well documented in the literature. It was first described by Hertig et al. in 1954.

The sections have been digitally restored and labeled, and can be viewed at two magnifications. Several 3D reconstructions have been generated from the aligned sections. Animations of these 3D-reconstructions are included on the disks.

Instructions for using the disks can be found by going to the Instructions section from the opening screen.