CTLL-2 assay help

Mark Doherty mdoherty at pop.niaid.nih.gov
Thu Jun 26 14:13:14 EST 1997

In article <19970626013500.VAA17945 at ladder02.news.aol.com>, dana32 at aol.com
(Dana32) wrote:

> Hello ! Can somebody out there provide me a method of calculation for the
> CTLL-2 assay ? 
> My e-mail address is Dana32 at aol.com
> Thank you !

It's pretty straightforward.  You need a standard - which is a growth
factor the CTLL-2 will respond to (normally either IL-2 or IL-15) at a
known concentration, which you can titrate onto your CTLL-2 cells at the
same time as you put your samples on.  How much of this standard you use is
going to varydepending on how much activity tere is in your samples, but
generally a good point to start your standard titration is about 10 u/ml,
and titrate down two fold from there.

Once you have a standard that overlaps the factor you have in your samples,
it's easy to calculate the activity ofthe samples.  If 1 u/ml of your IL-2
standard gives you 60,000 cpm and your sample gives you (say) 80,000 cpm
then you have 1.33 u/ml in your sample.  If your sample gives you 32,000
then you have 0.53 u/ml and so on.

Of course to attribute this activity to your growth factor of interest, you
should show that you can block it with saturating levels of the appropriate
monoclonal antibody.

Cheers, Mark

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