[RASMB] Ca measurement in solution

Wed Feb 13 18:22:08 PST 2013

Dear RASMB,

This is not directly related to AUC. I still believe that someone might be able to help.

We vary the amount of Ca in our protein solutions by having a constant amount of EGTA and add excess Ca to arrive at the level of Ca we require for our biochemical assays. To calculate the free Ca in this EGTA-buffered system we use Maxchealater (http://www.stanford.edu/~cpatton/webmaxc/webmaxclite115.htm).

With some extra bit of money made available to us, we are planning to buy a Ca-meter along with a Ca-electrode and a reference electrode. This will enable us to rule out the uncertainty in the Ca-levels arrived at by using the Maxchealater. When I explored I found Nova analytics (no commercial interest) have a Ca-meter and accessories. Unfortunately, I am not getting good pre-sales technical update from the local vendor.

I want to measure Ca-levels as low as 100 to 10 nanoMolar. 1 mM will be the upper end. Could someone help?

Regards,
Bala

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Balakrishnan Kannan , Ph.D.,
Institute of Molecular and Cell Biology,
BR Lab, Proteos,
61, Biopolis Drive,
Singapore 138 673
e-mail: bala at imcb.a-star.edu.sg<mailto:bala at imcb.a-star.edu.sg>
Ph: +65-6586 9831
Fax: +65-6779 1117
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________________________________
From: rasmb-bounces at list.rasmb.org [mailto:rasmb-bounces at list.rasmb.org] On Behalf Of Jake Marold
Sent: Thursday, February 14, 2013 3:54 AM
To: John Burgner
Cc: rasmb at list.rasmb.org
Subject: Re: [RASMB] ProteomeLab startup errors

RASMB,

Thank you to everyone who responded to my post for your comments and suggestions.  I wanted to reply with an update to the problem we encountered yesterday, as we seem to have resolved the issue.  As indicated in the README file associated with Version 6, problems with the interference camera upon startup sometimes arise from problems with the frame grabber driver.  I did not want to remove and uninstall the driver software files myself (mainly because I could not find back-ups to reinstall them in my immediate area).  Instead, I reset the camera configuration file MyCE2KE1.cam by running the SysReg utility.  What I discovered was that the camera configuration file path was leading ProteomeLab to a directory, which did not include MyCE2KE1.cam.  I simply corrected the path, and was able to collect interference data overnight.  We may never know why the path was spuriously changed, but at least there will now be a ?fix? in the RASMB thread for those encountering issues similar to these.

There is an added bonus in that my run terminated due to a comport error.  Fortunately it was towards the end of my data collection, but I don't think Version 6 is out of the water yet!

-Jake Marold
Johns Hopkins University
On Tue, Feb 12, 2013 at 8:27 PM, John Burgner <jburgner at purdue.edu<mailto:jburgner at purdue.edu>> wrote:
I might in desperation remove the camera controller board (after unplugging the power for both) and clean the contacts with a number 2 pencil  and reseat all of the connectors.  You have an advantage over the rest of us in that Erby Perdue lives in Baltimore and he probably will come see you before he comes to Richmond.
John Burgner

From: rasmb-bounces at list.rasmb.org<mailto:rasmb-bounces at list.rasmb.org> [mailto:rasmb-bounces at list.rasmb.org<mailto:rasmb-bounces at list.rasmb.org>] On Behalf Of Jake Marold
Sent: Tuesday, February 12, 2013 5:39 PM
To: rasmb at list.rasmb.org<mailto:rasmb at list.rasmb.org>
Subject: [RASMB] ProteomeLab startup errors

Hey everyone,

This afternoon, we received two errors whilst attempting to startup our ProteomeLab software (we have version 6):

Internal SDK error
Source file: BFBrdUsr.c
Line #: 1131
Error Code 4298
Message: Can't initialize for camera

R2CamUsr.c
Line #: 275
Error Code 4298
Message: Error reading configuration file

When I attempt to open an old scan file, or create a new one, the interference box cannot be toggled in the cell setup, nor can I play with the laser settings. The comport connections are connected securely from the back of the ultracentrifuge, and the blue lightning bolts flash, indicating connectivity.  The only abnormality is that our battery backup surge protector (connected only to the computer, APC Back-UPS RS 900 model) has its replace battery light blinking and beeping.  Given the error messages above, I don't anticipate this is our problem, but I also do not know.

Have any of you had any experience with an issue like this?  I was hoping to perhaps receive a quick-fix tip from you before calling Beckman.  Thanks in advance.
[%20]

-Jake Marold
Johns Hopkins University

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