light activation of Calphostin C?

[John Hines]

I ordered some Calphostin C (the PKC inhibitor) to use in signal
transduction experiments in transfected COS cells.

I found out that this compound must be "activated by light" before it will
achieve maximum inhibition.  What does this mean?  Does it mean I have to:

-  expose the stock solution to light before adding it to the cells, and
then incubate the cells in the dark?

-  incubate the cells in the presence of light while they are exposed to
the inhibitor?

 
I guess I was a bit naive -- if anyone works with Calphostin C in
experiments like this, I'd love to hear how you "light-activate" the
compound.


John

hines at pharm.med.upenn.edu