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April 22, 2010:
900 MHz Salt Tolerant Cold Probe Installed

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900 MHz Salt Tolerant Cold Probe Installed

We are delighted to announce that the Rocky Mountain Regional 900 MHz NMR Facility is now equipped with a cryogenic probe.  The probe is the latest generation Varian probe, equipped with salt-tolerant capability. In addition, the probe is carbon enhanced for direct C13 detection.

This probe boasts a signal-to-noise of up to 7500:1 for ethylbenzene, translating to a s/n of 1100:1 for sucrose.  In addition, the salt tolerance of the probe allows us to achieve a sensitivity of 400:1 for 250 mM NaCl sucrose, almost doubling the performance of the room temperature probe for this salty sample. This is achieved using two 2.5mm tubes, which are available from Shigemi, Inc (BMS-0025), and are much easier to handle than the 3x6 rectangular tubes from previous salt-tolerant generations.

We are a full service facility, if you send your sample to us we can handle experiment setup, data analysis and even collaborate with you to accomplish backbone assignments if desired.  This way we streamline data collection, allowing you to focus on research.  We can usually accommodate time requests within a few weeks, and are happy to allocate time in up to two-week segments.  Our goal is to tackle the challenging projects that may not be feasible at other facilities.

We hope that you will keep us under consideration for your high-field NMR needs, if you have any questions about the facility or about the performance specifications of the new cold probe please do not hesitate to contact us.

Geoff - April 22, 2010

800 MHz Salt Tolerant Cold Probe Up and Running

We would like to announce the successful installation of a salt-tolerant, C13 enhanced cold probe on the 800 MHz NMR spectrometer at the University of Colorado.  This probe allows the use of special Shigemi "S-tubes" (available from Varian) to obtain higher signal-to-noise for salty (>250 mM NaCl) samples.  In addition, the cold C13 preamp allows one to obtain natural abundance C13 spectra for less concentrated samples.  The proton signal-to-noise for this probe is in excess of 6000:1 for the ethylbenzene standard.

If you find you have a need for the capabilities of this probe please do not hesitate to contact me, or Dr. Pardi for information on rates and how to send samples.

Geoff - January 28, 2009

800 MHz Salt Tolerant Cold Probe Arrives

A new salt-tolerant, carbon enhanced cold probe has been installed at the W. M. Keck 800 MHz NMR facility! Tests will be performed for several weeks before we open the spectrometer back up for users.
In addition, the spectrometer host computer has been upgraded to a Linux system running VNMRJ 2.3A. This new software will allow us to monitor the cold system directly, rather than through a cryobay.
The new probe file can be found under /vnmr/probes/HCN, make sure that you have loaded this before you set up new experiments. Geoff - October 17, 2008

Room Temperature Probe Returned

The room temperature probe for the 900 MHz system has been returned from repair. First impressions are that the system is back up to full speed. One note of caution, however, is that the N15 channel is still having problems making the specification for the pulse width. But it can achieve 38 us at a power level of 60, which should be plenty. As a precaution it may be best to back off on the N15 pulse power in experiments that have a large number of pulses (i.e. CPMG, T1rho, etc.).
The calibrations for the probe hold true to those previously recorded so parameter sets/pulse shapes from before March 30th should be okay to use. A list of calibrations are available here.
Once again the BioPack probe file can be updated as was outlined in a previous news item.
Geoff - June 17, 2008

New Calibrations for the 800 and 900

I have done new calibrations for both the 800 and the 900.  These were performed using the salty (250 mM) auto-test solution and so they should well approximate your sample conditions.  This should give you a good jumping off point for your sequences that you run through the BioPack interface.  To update your probefile, open VNMRJ and set BPinstall=0.  Then exit and restart VNMRJ.  Under the Experiments Menu --> Protein Triple Resonance --> Activate BioPack, choose the "Activate BioPack with copy of VNMR1 probe file."  This will copy the new probe file to yours.  When it is done, go to the Setup Tab --> Globals & Probefile and choose the update probefile option (it is under a ghn_co experiment).  Once it has made all the new shapes, exit and restart VNMRJ.  Sorry that this is so clunky, but I have not found a better way to do it.
The website has also been updated with the new calibrations, so you can check to make sure the parameters get pulled up correctly.  Note that the experiments will only reference the new probefile if you choose the experiment from the menu or issue the macro at the command line.  If you pull up an old parameter set you will have to enter the parameters by hand.
Things to note for all users (not just BioPack): neither probe can handle that much carbon power at this point, so the carbon power (pwClvl, pwxlvl1, dhpwr) should not be set higher than 60.  This gives a pulse width of 14 on the 900 and 13.6 on the 800.  Also, check that the parameter gradientshaping='y' in your account.  Once this has been done the first time it will not have to be set again.  In this case if you will be running any of Lewis Kay's sequences, check that the "rgradient" statements have been replaced by "zgradpulse" ones.  If you are not sure how to do this, let me know and I will help out.  Finally, if you are running on the 900, make sure that pfgon='nny'.  The X and Y gradients are non-functional on the loaner probe and if you have it set to something else, the Z gradient will not come on either.
As always I am happy to answer any questions any of you may have.
Geoff - April 11, 2008

900 MHz RT Loaner Probe

We have received a loaner probe for the 900 MHz NMR for use while the room temperature probe for the system is repaired. This probe has some limitations, but it should take us through the repair period well.
If you have any questions about the performance of this probe, please contact me and I will be happy to provide information.
Geoff - April 4, 2008

900 MHz RT Probe Repair

The room temperature probe for the 900 MHz system has been sent back to Varian for repair.
The probe was arcing on both carbon and nitrogen channels, confirmed using the RF homogeneity tests for those two nuclei. As the probe is essentially useless without triple resonance capabilities it was sent back for repair immediately. I have scheduled two weeks of downtime for this repair, but hopefully it will be less than that.
Geoff - March 31, 2008

600 MHz Cold Probe Re-Installed

Cold probe is up and running on the 600. With the Dell Linux VNMRJ2.1B and the cold probe the system is ready for use. I have calibrated probe files for vnmr2 and vnmr3. New shims and basic calibrations such as S/N tests are in vnmr1.
Murali - March 21, 2008

600 MHz Spectrometer Upgraded to 2.1B Linux Workstation

The 600 INOVA now has a Dell computer with a widescreen monitor to control the spectrometer and the computer is named inova600D. It runs the same VNMRJ2.1B as the other systems. The BioPack is loaded and calibrated probe file is available. I have copied vnmr2, vnmr3 user files from the sun which is also in the network. As you use this system, if you find any of your files missing you can easily get it from the sun. As you use the Dell you may find the widescreen display has its own characteristics as there is more horizontal real estate than vertical, thus forcing some scrolling up and down.
As of now the spectrometer has the Nalorac room temperature probe. The cold probe is still in repair with Varian and I am waiting for them to give me an expected return date.
Murali - February 27, 2008

New Website Goes Live

The new website for the University of Colorado NMR group is now online!
The website combines the resources for the two high-field NMR facilities at the University of Colorado along with the lower field instruments from the Department of Chemistry and Biochemistry. It is our hope that this format will better serve our users, and the NMR community.
Geoff - February 27, 2008