CHO cell clumps in bioreactor - (Apr/20/2001 )
We are looking for protocols/technics/tricks (such as the addition of DNAase 1) which can avoid the clumping/aggregation of mammalian cells (more specifically, CHO K1) cultivated at high density in perfused bioreactors.
Thanking you in advance
Try to use serum- and proteinfree medium and cells that growing under this conditions (see www.eugenex.com)Axonlab distributes a anti-clumping solution, but this is expensive for an bioreactor and consists proteases which may degrade your protein of interest.
We have been worked on the massive CHO-k1 cell culture in our lab,at El-Azhar University,for at least one year now.We be began with culture conditions as:Ham's F12/5% FCS/5% CO2.It worked fine without any clumping observedwhatsoever.Even with a slight deviation in the culture conditions of adding only 3%FCS to the medium.of course,It slowed down the growth rate of the cells and also with no clumping observed.Since 4 months,we grow it in the absence of CO2.I'm looking forward of your reply and you are always welcome in any exchange of experience.Bye Bye..
I also faced the same problem of clamping of CHO -KI in bioreactor, lastly we concluded the reasons for clamping in bioreactor.
1. high agitation speed
2. high aeration, usually had a passion to supply air as surface aeration at high flow rates.
3.and lastly fungal contamination.
by decreasing the aeration and agitation rate, clamping can be eradicated in bioreactor.
The technical Bulletin on avoiding cell clumping is attached; it's for insect cells but I believe you will find it useful. I myself have tried using heparin and it worked wonders.
Sorry I missed attachment in above reply.
If any one have good literature on how to avoid CHO cell clumping in bioreactors level.
thanks in advance..