Replies to Ca/EGTA buffer question

Fergus_Doherty at vme.ccc.nottingham.ac.uk Fergus_Doherty at vme.ccc.nottingham.ac.uk
Thu Sep 17 05:15:02 EST 1992

A short while ago I posted a question to the net regarding the use of 
Ca/EGTA buffers, and more specifically whether there were any PD 
programs available to calculate free Ca concentrations in such systems.
This is a summary of the replies.
1.  Gregg Cohen suggested adding EGTA then dialyzing the enzyme to remove 
all the Ca, then adding back Ca.
2.  David Lapointe sent a listing of his program, COMICS (Perrin + Sayce, 
Talanta, 14, 833, written in C which compiles with TurboC(++), for the PC.
He can be reached on lapointe at edu.uthsega.thorin.
3.  Jochem Kleinschmidt described his MSDOS program, CABUFFER, which he 
3.  Jochem Kleinschmidt described his MSDOS program CABUFFER which he 
recently sent a msg to the net about. Available by anonymous ftp 
from mcclb0.med.nyu.edu ( More details in his recent 
4.  Jim Gabern sent me by e-mail a program, Free Ca, written by a student 
of Claude Klee, NIH.  This is available, he says, from ftp.embl-heidelberg.
de.  Be warned, this is a slow process from this site.  This is the 
program I used.  It will calculate free Ca given EGTA, EDTA, ATP, Na, 
K, phosphocreatine total concentrations, and also allows you to enter 
new ligands, provided you have the stability constants. Oh, and it
obviously allows for pH.
5. Ron Grunwald mentioned a program by Fabiato described in Methods in 
Enzymol. 157, 378 (1988) and CHELATOR, by Schoemaker described 
in BioTechniques 12, 870 (1992).
Thanks to everyone who replied, as I said it shows the usefulness of 
this net, so thanks also to those who run it.
Fergus Doherty, Biochemistry, Nottingham University, UK>

More information about the Bio-soft mailing list

Send comments to us at biosci-help [At] net.bio.net