why not iPSC derived HBEC without immortalisation gene that will interfere?

Hello Umeshi Karunadasa

1. Is starting experiments at passage 18 considered late for this cell line? If not, how long can we keep safely passaging this vial?

Generally, not specific to HBEC-5i cell line, in vitro experiments are performed at a relatively low passages, for instance, P10 – P20, before returning to another ampoule of the same stock. It is better to start your experiments below passage 10, though passage 18 is not late, but changes in cell morphology and behavior would be seen.

2. Will there be any differences from cell morphology & behavior, compared to early passages?

Yes. There will be a difference in cell morphology & behavior. But the difference is not seen until passage 10. After passage 10, the differences in morphology and behavior are noticeable.

3. Are there places in UK that we can get HBEC cells at a lower passage than this?

You may check the European Collection of Authenticated Cell Cultures (ECACC) catalogues. ECACC is a part of Public Health England. I doubt they have this cell line, but please confirm. You may also look out for private vendors such as Merck Millipore and Sigma. Outside UK, you may get this cell line from ATCC in the US.

4. Is it better to use hCMEC/D3 cell line instead of HBEC-5i in a scenario like this?

Both hCMEC/D3 and HBEC-5i cell lines can be used to model the human blood-brain barrier in vitro. hCMEC/D3 is a good choice for studying drug uptake and active transport. It is also useful if your study involves understanding how the brain endothelium responds to pathogens and inflammatory stimuli.

On the other hand, HBEC-5i cell line expresses tight junction-associated proteins, and has low permeability and high TEER. It has been shown to have potential for permeability screening. So, it all depends on your experimental requirements.

Best.

Thank you so much!