As a 1st time user of BEAS-2B cells (human bronchial epithelial cells), which I'm starting to culture, I've noticed that they've been growing really slowly ....

They were acquired by ATCC no passage number, but there's little to no explanation on handling the cells, apart from culture media used.

Not sure if it's the centrifuge force I'm using (1500 rpm for 5 mins) .... but they take 4/5 days to grow.

Any ideas or suggestions?

Thank you.