Problem with seeding density
Posted 10 February 2011 - 10:11 AM
Posted 10 February 2011 - 05:12 PM
Posted 12 February 2011 - 07:40 AM
Posted 12 February 2011 - 03:20 PM
The 24 hours is so that the cells which you are using to condition the medium don't use up all the nutrients, but still have secreted some growth factors into the medium. The filtering is so that you don't have cells from another cell line ending up in your culture causing a contamination, which is a big problem... there are estimates that approximately 1/3 of cell cultures are actually variants on HeLa from these sorts of contaminations, or to prevent cells in the conditioned medium stuffing up your seeding densities.
Conditioned medium does not keep well, store in the fridge for a few days or frozen at -20 for about a month.