Polarized-light microscope facilitates major stem-cell advance

A polarized-light microscope played a key role in a major turning point in stem-cell technology: the derivation of embryonic stem cells from reprogrammed monkey skin cells. Scientists at the Oregon National Primate Research Center (Beaverton, OR), who first reported the advance last November, used the Oosight microscope from Cambridge Research & Instrumentation (CRi; Woburn, MA) to identify and remove the meiotic spindle and associated genetic material from 304 rhesus monkey eggs. The group then inserted genetic material from the skin cells of an adult male rhesus monkey into the enucleated eggs.

The reprogrammed eggs grew to the blastocyst stage, from which the team produced two stem cell lines genetically identical to the male monkey. The advance, the first derivation of such stem cells from a primate, points the way to the production of custom tissues that could combat a range of human diseases.

“Before, the problem was always that you could not see the spindle in the egg,” explains team leader Shoukhrat Mitalipov. “The only way to see it was to stain it with dyes. That, we found, was very detrimental for egg quality.” Contact Shoukhrat Mitalipov at [email protected].