What are the reliable tests for proof of pluripotency?

Proof of marker genes: Genes like Oct4, which are silent in differentiated somatic cells, are switched on in iPS cells. Proof of teratoma formation: If pluripotent iPS cells are injected under the skin of mice, a special form of tumor, known as a teratoma, develops. This growth contains different types of somatic cells and is similar to embryonic tumors with the formation of the [...]

What is the survival rate of single cell cloning in the DEF-CS system

The best we have seen is at around 50%. Less robust cells can still achieve 15-25%. The important things is that pluripotency is maintained for these single cells grow into clones and transfer out. Stem cell [...]

What are the common pluripotency markers?

SSEA1, SSEA4, Tra-1-60, Tra-1-81 and Oct-4 (nuclear), Nanog, Sox2 Stem cell [...]

Does cell morphology change with different culturing systems?

Yes. Scientists at Takara Bio have generated some interesting FACS data showing that iPS cells that were transferred from DEF-CS to competitor medium (E8, mTeSR, StemFit) changed back to the pattern that is originally observed in each medium. And they showed similar results for cells originally cultured in competitor media and then transferred to DEF-CS. So this flexibility should [...]

Can DEF-CS be used to differentiate cells if additional factors are added?

We use so called PTM medium (pre-treatment) which is DEF-CS basal medium without some of the components, i.e. not the DEF-CS basal medium. We have started an internal discussion here regarding information we can give to customers on differentiations protocol, so hopefully we can come up with some recommendations together with you. Stem cell [...]