Greetings to all colleagues!

Please persons who have experience of working will the cell line HEK293FT. Exactly "FT" not just 293T. The HEK293FT is used for packaging lentiviral vectors and this line is quite efficient for packaging but difficult to grow in even monolayers.

Both lines are adherent, but HEK293FT are much different from parental 293T cells in that FT tend to grow in clumps and do not form even monolayers during long-term growth. One need to re-plate these cells to achieve even distribution.

We manage to grow FT subclone in still cultures in flasks, etc. But we also want to use roller bottles. We have a CO2-incubator with installed roller, and want to grow FT in rotating bottles.

However it appears that these cells grow (in a roller) in large and small clumps and do not form monolayers on the bottle surface.

My questions:

- Does anyone here has experience with a similar situation?

- What plastic (manufacturer) do you use to achieve good growth of poorly-attaching cells in roller bottles?

- Do you pre-treat the bottles with anything to improve the attachment?

- What do you think about a possibility of adaptation of such cells to grow in a roller - specifically what is the best strategy: to try to select a further subclone which forms layers and not clumps in a rotating bottle; or on the contrary, select a subclone adapted for suspension growth? I have a choce of these works and need advice where to go further.