I've recently bought a batch of progenitor cells isolated from a human fetus from DVbiologics. When culturing them however, I've run in to some problems. There seems to be some kind of contamination inside the cells (see attached pictures). Small black dots that seem to prefer to reside around the nucleus. In some cells there are many, in some few and in some none. I think they are visible in the media outside the cells as well, but that could just be cell debris. There is no change in pH and the cells are quite healthy(~95% viability).
I've taken up a fresh batch from the freezer: they appear. I've sterile filtered everything, yet still they appear. They seem to be impervious to pen-strep. They do not stain with DNA staining dyes and the extracellular ones (debris) seem to ignore the concept of alkalic lysis. When a sample of cell culture media is incubate in sterile LB media, nothing has grown after a few days.
When appearing extracellularly, they appear to vibrate, but inside the cells they seem to be stationary. They are driving me mad! Does anyone have any thought what this might be??
Edited by elpollodiablo, 23 September 2010 - 05:52 AM.