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Measuring molecular interactions by multi-wavelength analytical ultracentrifugation Registration Here!


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Analytical Ultracentrifuge

The analytical ultracentrifuge (AUC) monitors sedimentation process of particles in solution, including proteins, nucleic acids, carbohydrates and polymers. By using different experimental setups, namely sedimentation velocity (SV) and sedimentation equilibrium (SE), the instrument is capable of determining molecular weights (hence, oligomeric states), sample purity, conformations, self- or hetero- association properties. The instruments in BCF are Beckman Coulter ProteomeLab XL-A and XL-I. XL-A is shared by the Institute of Biological Chemistry to Academia Sinica community for research purpose. It has absorbance optics (190nm-800nm). XL-I is equipped with two optical systems, absorbance and Rayleigh interference. Rayleigh interference optical system provides possibility for large molecules which sediment too fast for absorbance system or samples with no absorbance or high absorbance backgrounds. Furthermore, it offers wider dynamic ranges for association studies. Users may specify detection systems, Rayleigh Interference and/or absorbance, along with experimental methods, SV or SE, upon filing sample submission requests through BCF reservation system. Miss Szuhuan Wang will perform the experiments according to user specified parameters or the standard protocols described in AUC sample submission guideline.

Important Notification:

* (2015-09-08) XL-A is restored. However, the aging pump leaking oil can cause problems occasionally. Sorry for the inconvenience.

* (2015-08-28) XL-A is shut down due to a pump problem, leaking oil and causing early termination of data acquisition. Sorry for the inconvenience.

* (2013-08-22) XL-A is restored.

* (2013-08-19) XL-A is not available because of low level of rotor drive oil (DIAGNOSTIC 66 RECEIVED). Beckman service has been nitified.

* (2013-07-01) Recently, the instrument was not effectively operated because of several dropped cases resulting from user's carelessness. Therefore, we are adding a penalty in the sample submission guideline, "if experiments are abort because samples do not meet the criterion of the AUC experiment stated in the sample submission guideline, for example, sample absorption < 0.1 or >1.0, BCF will charge $150 per cell for setup and cleaning." Users are encouraged to use BCF's UV/VIS to check the absorbance of buffers as well as samples, free of charge.

* (2013-07-01) XL-I is ready for sample submission (SV or SE with Rayleigh interference and/or UV/VIS absorbance optics).

* (2012-10-30) XL-A is restored and ready for SV sample submission (UV/VIS detector only).

* (2012-10-11) XL-A is out of service because of low light intensity, possibly from dirty lamp or slit.

* (2012-07-31) The rotor drive of XL-I was badly damaged possibly because of a sensor malfunction. BCF will resume all AUC service when the problem is resolved.

title Related Softwares

For buffer density and viscosity estimation: Sedntrep(version 20111201 Beta);
For AUC data analysis: Sedfit, Sedphat, UltraScan, LAMM, DCDT+ and SVEDBERG;
For hydrodynamic modeling: US-SOMO, HYDROXXX.

title Suggested Reading:

Beckman Coulter Lab Resources for ProteomeLab XL-A/XL-I

Andrea Balbo and Schuck P, 2005, in: Protein-Protein Interactions: a molecular cloning manual 2nd ed., Chapter 14, Cold Spring Harbor Laboratory Press, 253-277.

Lebowitz J, Lewis MS and Schuck P, 2002, Modern analytical ultracentrifugation in protein science: A tutorial review, Protein Science, 11, 2067-2079.