The human embryonic stem cells available for research are contaminated with nonhuman molecules from the culture medium used to grow the cells, researchers report. The nonhuman cell-surface sialic acid can compromise the potential uses of the stem cells in humans, say scientists at the University of California, San Diego. Their study was published Sunday in the online edition of Nature Medicine.
It's been known for some time that the lines qualifying for US Federal funding were essentially useless for serious science - for this and other reasons. Several better methodologies for developing uncontaminated lines have been developed. I'm not sure that this latest study is saying anything new, despite all the attention.
A number of other lines, such as those developed by Douglas Melton, are available for private or state-funded research - a good thing too, since a large number of lines are needed to get anywhere.