Defined and serum-free media support undifferentiated human embryonic stem cell growth.

Four commercially available serum-free and defined culture media tested on 2 human embryonic stem cell (hESC) lines were all found to support undifferentiated growth for >10 continuous passages. For hESC cultured with defined StemPro and mTeSR1 media, the cells were maintained feeder-free on culture dishes coated with extracellular matrices (ECMs) with no requirement of feeder-conditioned media (CM). For xeno-free serum replacer (XSR), HEScGRO, and KnockOut media, mitotically inactivated human foreskin feeders (hFFs) were required for hESC growth.

Identification of proteins from feeder conditioned medium that support human embryonic stem cells.

The maintenance of undifferentiated human embryonic stem cells (hESC) requires feeder cells, either in co-culture or feeder-free with conditioned medium (CM) from the feeders. In this study, we compared the CM of a supporting primary mouse embryonic feeder (MEF) and an isogenic but non-supporting MEF line (DeltaE-MEF) in order to gain an insight to the differential expression profile of secreted factors. Using two-dimensional electrophoresis (2-DE) and matrix-assisted laser desorption/ionization-time of flight (MALDI) tandem mass spectrometry, 13 protein identities were found to be downregulated in DeltaE-MEF compared to MEF, of which 4 were found to be soluble factors and 3 proteins were membrane-associated or related to the extracellular matrix.