Colorized scanning electron micrograph of a human embryonic stem cell (gold) growing on a layer of supporting cells (fibroblasts). Stem cells are derived from very early embryos and can either be grow...

Human embryonic stem cell colonies that have been stained for alkaline phosphatase (red). Alkaline phosphatase staining is used to show that the colonies are pluripotent. The colonies are growing on a...

Thick microtubule bundles are organized around the periphery of each stem cell in human embryonic stem cell colonies. Human embryonic fibroblasts were grown on a layer of mouse embryonic fibroblasts w...

Movie showing human stem cell colony migration.

Zebrafish embryo at 75% epiboly. The view is from the animal pole. The focal plane is deep within the blastoderm. The focal plane changes as the embryo rolls during the sequence. The fluorescent lipid...

This time lapse series illustrates the early division up to the four-cell stage of a wild-type C. elegans embryo by DIC microscopy. The first C. elegans embryonic division of the P0 zygote is asymmetr...

Zebrafish development from early cell division to axiation and onset of muscular contractions. Video made avaialable through Mark Cooper and Zebrafish - The Living Laboratory.

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...

Cultured chicken embryonic cardiomyocyte fixed and stained for alpha-actinin using a monoclonal antibody and Alexa-546 as a secondary fluorescent antibody. Imaged by widefield epifluorescence on a Zei...

Fluorescent micrograph of differentiating mouse embryonic stem (ES) cells. Embryonic stem cells are pluripotent, meaning that they have the ability to differentiate into any cell type depending on th...