U937 monocyte suspension culture adhering to flask. Why?!

giwamot at indycms.iupui.edu giwamot at indycms.iupui.edu
Thu Nov 17 12:10:06 EST 1994

In article <39vjpt$ekm at mserv1.dl.ac.uk>, <psansom at hgmp.mrc.ac.uk> writes:
> Relay-Version: ANU News - V6.1 08/24/93 VAX/VMS V6.1; site ivax
> Path: 
> Newsgroups: bionet.molbio.methds-reagnts
> Subject: U937 monocyte suspension culture adhering to flask. Why?!
> Message-ID: <39vjpt$ekm at mserv1.dl.ac.uk>
> From: psansom at hgmp.mrc.ac.uk (Mr. P.A. Sansom)
> Date: 11 Nov 1994 11:16:13 -0000
> Sender: lpddist at mserv1.dl.ac.uk
> Distribution: bionet
> Original-To: methods at dl.ac.uk
> Lines: 34
> OK, to set the scene
> Little me growing U937 monocytic cell line in
>     RPMI 1640
> with
>     2mM L-glutamine
>     5% heat inactivated fetal calf serum
>     5% CO2 humidified
> in
>     Falcon tissue culture flasks (plastics)
> Problem is that they have started adhering to the plastic of the flask, 
> it hard to harvest them as intact cells for my expts. I have just made up a
> fresh bottle of medium, so I assume that its something to do with that, but
> what? All the components are the same ones that I've been using all along,
> stored as frozen aliquots apart from media which are 1X liquids.
> I've seen similar before when growing cells in methionine free medium, but I
> don't see that the medium can be deficient in any amino acid, unless the
> L-glutamine is off.
> If anyone has any ideas, or has experienced similar problems, please let me
> know.
> Thanx in advance
> Paul
> psansom at hgmp.mrc.ac.uk
> Paul A Sansom                                  tel: 081-748-9966 x4208
> Department of Biochemistry                     fax: 081-748-5090
> The Kennedy Institute of Rheumatology
> 6 Bute Gardens
> Hammersmith
> London W6 7DW

Adherence of U937 cells occurs as the cells are differentiated.  
Difeerentiation may occur from a variety of stimuli including TPA, retinoic 
acid, and contaminants such as endotoxin.  I also have had changes occur when 
the cells were not passed often enough and the cell density became to high ie 
>1X10^6/ml.  We also use 10% FBS in our culture medium.

More information about the Methods mailing list