Actually both the assay's have significance in their own ways. the EB formation assay is an invitro assay to confirm the ability of the cells to form clusters and get differentiated to all the three lineages. While the teratoma assay is to conifrm the ability of stem cells to fom teratomas in vivo. Even if the cells have the ability to form EBs does not mean they are teratogenic. hence neither assays can replace each other.

Hi, I agree with the previous answer and I also suggest you to have a look at the Nature protocol I'm attaching, I think it's a very useful guideline for human pluripotent stem cells characterization.

Good luck!

I think both assay is necessary.

Both assay are important to assess pluripotency.

If you can only choose one, teratoma assay is better.

Agree with answers given here, both are complementar but teratoma is ultime confirmation of the pluripotency.

Thanks for the paper, Tania.

Thanks for all the answers so far. Shabari, Debasree, Stephane, Chan-Jung, Leila - if one were to focus solely on the biology revealed by the two assays (not on cost or convenience in this particular case), is there qualitatively different information between the two? My hunch is that teratoma shows all the information given by EB + more, as Sandy was suggesting. If that is true, I wouldn’t think of them as complementary, but less and more informative respectively. On the other hand, are there qualitative differences between how the two assays are done, which reveal different aspects of PSC biology, unrelated to stemness, and which would make them complementary assays?

If teratoma formation is more stringent, I am guessing that the information must have come from mouse studies where they probably correlated outcomes of both assays to that from tetraploid complementation. Does it also mean that certain cell types show up in the teratoma assay that may (or may not) show up in the EB assay? If true, that may be a way to grade EBs based on the cell types they show (not just a YES or NO score, but on a scale), in relation to corresponding outcome in a teratoma or even better, a tetraploid complementation assay?

I have updated my original question with these new questions that arose based on the responses so far.

I should add, that correlative approach would work in mouse models only.

To determine if a cell is truly a pluripotent stem cell, it is important to verify its ability to differentiate into each of the three germ layers. The teratoma assay is a standard way to assess pluripotency, but this method requires expensive animal models and is time-consuming, often requiring 6 to 10 weeks before pluripotency status can be determined. Similarly, embryoid body assays are less time-consuming and rely on random differentiation.

Masuma