Hi All,

I am not a calcium specialist but if free calcium concentrations will
change due to release from the fluorchrome, one can state that the
incorrect amount of fluorochrome is used.
The principle should be that the fluorochrome concnetration must be that
low that it does not buffer the calcium concentration. It has to be the
same as with a ph indicator. This indicator, although it reacts with
protons may not change the net amount of free protons in a significant
way, otherwise it works as an buffer and not an indicator.

This is also one reason why fluorescent dyes are used. They are visible at
extreme low concentrations and give a signal without affecting the
concentration to a significant amount.

What is significant: 1% I guess is reasonable.


Patrick

 On Wed, 30 Sep
1998, Doug Hubatsch wrote:

> Hi All,
>
> Anybody know what happens to the calcium and/or the dye after they have
> bound together and been through a cycle of excitation and emission?  Does
> the dye undergo a physical change (?) which results in the calcium being
> released?   If so, is the dye 'weaker' during the next cycle?
>
> Regards,
>
> Doug
>

______________________________________________________________________
     =======            Patrick Van Oostveldt
   ===========          Lab. Biochemistry & Molecular Cytology
    | | | | |           FLTBW
    | | | | |
   ===========          Coupure Links 653
 ===============        B 9000 GENT

                        tel: 32 9 264 5969
                        fax: 32 9 264 6219