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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 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.

-sanjay Gottipamula-

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..