I apologize for the paucity of posts. Between our trip to the American Society of Reproductive Medicine Annual Meeting in Atlanta to our Internet Service Provider “upgrading” our site this weekend (which actually caused more problems than I care to remember), we have been a bit predisposed. However, almost everything seems to be back in working order and hopefully the site will load much quicker now.

A friend emailed me this spectacular photos all taken with a scanning electron microscope:

Human Embryo
Scanning electron micrograph of a human embryo at day 4. The protein coat surrounding the egg (zona pellucida, gold) has been slit to expose the embryonic cells inside (red). These cells go on to form the embryo and can be harvested and cultured to give rise to embryonic stem (ES) cells. Microvilli are visible on the surface of the embryonic cells (blastomeres) and numerous sperm (blue) are still visible on the outside of the zona pellucida.

Six Day Old Human Embryo
A 6 day old human embryo beginning to implant into the lining of the uterus (endometrium).

Sperm on the Surface of a Human Egg
A close-up of sperm attempting to fertilize an egg.

Human Egg with Coronal Cells
This image is of a purple, color-enhanced human oocyte. The egg is coated with the zona pellicuda, a glycoprotein that protects the egg but also helps to trap and bind sperm. Two coronal cells are attached to the zona pellicuda.

Human Embryo and Sperm
An oocyte, five days after fertilization with some remaining sperm cells. This fluorescent image was captured using a confocal microscope. The embryo and sperm cell nuclei are stained purple while sperm tails are green. The blue areas are gap junctions, which form connections between the cells.

You can find some more spectacular photos here.