This cross section shows a human fetal testis. Numerous seminiferous tubules appear within a lobe of the testis. It has not been treated with an antibody but is autofluorescent and therefore appears b...

Scanning electron micrograph of a hamster oocyte cumulus complex. Cumulus cells (purple) and matrix (gray) are shown. Small blood clots (red) also often appear in oocyte cumulus complexes. The red blo...

Hamster sperm fertilizing a hamster oocyte. This scanning electron micrograph shows hamster sperm fertilizing a hamster oocyte. Fertilization was performed in vivo. Sperm are shown binding to the out...

Surface of a mouse oocyte This transmission electron micrograph shows the cortex of a mouse oocyte that was undergoing fertilization. The sample was fixed using glutaraldehyde and osmium tetroxide, em...

Chick Chorioallantoic Membrane (CAM). This scanning electron micrograph shows a section through part of a chick chorioallantoic membrane. A blood vessel has been fractured in the middle of CAM reveal...

Surface of the zona pellucida surrounding a hamster oocyte. This scanning electron micrograph shows the zona pellicida around a hamster oocyte at high magnification. The zona pellicida has a complex ...

Human embryonic stem cell colony. This phase contrast image shows a human embryonic stem cell colony growing on Matrigel, a substrate that supports attachment of hESC. The Matrigel forms a thin coatin...

Human embryonic stem cell colonies. This phase contrast image shows two human embryonic stem cell colonies growing on a feeder layer of mouse embryonic fibroblasts. The stem cells actually grow in bet...

Fluorescent image of a mouse oocyte labeled with an antibody to tubulin, which is shown localized in the cortex of the oocyte. The sample was fixed in paraformaldehyde for subsequent immunolabeling wi...

Chick Chorioallantoic Membrane (CAM). This scanning electron micrograph shows a section through part of a chick chorioallantoic membrane. A blood vessel has been fractured in the middle of CAM reveal...