In article <4ugqnd$ap3 at nuscc.nus.sg>, mcbthy at leonis.nus.sg (Tang Hsin Yao)
wrote:
> Hi! Does anyone know how to add Calcium Chloride (CaCl2) into YPD? I have
> tried to make YPD plates supplemented with 100mM CaCl2. I first dissolved
> the CaCl2, then I added the usual stuff for making YPD. But after I
> autoclaved the solution, the CaCl2 seems to ppt out. Do I need to adjust
> the pH or something? I have done the same thing with MgCl2 and there was
> no problem. Please advice me on what to do. Thank you very much for your
> kind attention.
>>> Hsinyao Tang
>mcbthy at leonis.nus.sg
Hsinyao,
The calcium will precipitate from pH 6- pH 7. You can buffer the
plates to pH 5.5, which will help a little. You caN also aseptically mix
sterile calcium chloride into your autoclaved YPD (we autoclave with a
stir bar in the flask, add extras, stir and pour. This technique greatly
reduces bubbles in the plates.). In my experience, the slight ppt you see
will not greatly affect the availabilty of calcium to the cells. If you
need really precise concentrations, you should probably dot the whole
thing in liquid media anyway.
Kevin
--
Kevin A. Morano
Thiele Lab
UMich Medical School
kmorano at umich.edu
