Embryonic Stem Cells: Great Tools Require the Right Maintenance

Blog entry

I’ve spent many hours preaching to students, colleagues, and even perfect strangers  (at least the ones that stuck around long enough to listen) about having the right tools for the right job. Perhaps I should have spent a little more time on the importance of maintaining one’s tools so they do what they’re supposed to do….And what better place to do this than a blog about embryonic stem (ES) cells?


ES cells are a finicky bunch. We all know it, and we all go back to the cell room everyday and make sure we don’t do anything to irritate those little “organ seeds.”  We are at their beck and call, we cater to their whims, we feed them, we give them support, we give them everything they ask for just so we can wait for that fateful day when we get to tell them what to do: Make neurons, make hepatocytes, make cardiac muscle. But anyone who’s spend even a semester with these cells know this: Screw it up in the beginning (or any other time for that matter) and you’ll be tearing your hair out trying to figure out why you have no surviving cells, or why your numbers are so low, or worse: why you can’t reproduce your “Cell Press worthy” findings.
Well, no need to worry.  I am after all, going to share a few simple things that helped me along the way. Many of you may be rolling your eyes at this but hey, maybe one of you out there will benefit from this!
1-Use your medium within 3 weeks of mixing it up. I’ve found that you can stretch it to a month if you put another round of glutamine in it…but it’s a short term fix and should be used only if you can’t make new stuff right away.
2-Don’t get comfortable with your serum supplier (Even if it’s Gemini!).  Always request a certificate of Analysis (Gemini publishes theirs) and don’t be afraid to ask how they qualify their FBS as “ES-grade”.
3- Take careful notes of your observations and don’t be afraid to take a picture or two of your ES cells. For example, I would take a picture of my ES cells after they recovered from a thaw, then again every few passages. It was a good way to monitor colony morphology and keep me from using them for too many passages.
4-Try your serum with and without heat-inactivation. Most labs don’t need to do this anymore, as sterile-filtering and GMP regulations really preclude the need for it…..UNLESS you’re worried about complement, or you’re in an immunology lab and don’t want to risk it.
Well, that’s about it, for the generic ES-type maintenance. Stay tuned for specific stuff as we get this blog rolling!