Circular dichroism

Circular dichroism

The Shared Instrumentation Core houses an Aviv 410 circular dichroism spectropolarimeter. The spectra provide information about protein structure, and more often, changes caused by temperature or solvents.

Common experiments are observing changes in helical structure caused by changes in the solution or protein sequences, and observing changes in melting temperature caused by changes in solvent, stabilizing molecules, changes to the protein sequence. Several programs estimate the amount of helix, sheet and coil in a protein, with estimates dependent on the program used and the wavelength range used.

The instrument is user operated with a usage fee to cover the cost of high purity nitrogen and other supplies and maintenance. The core can give introductory training to new users. Each laboratory has an account on the computer which runs the instrument.

The Core has cells with path lengths of 2, 5, 10 mm. Phosphate buffer (without salt) gives the best wavelength range for taking spectra.

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The Aviv manual and locally written instructions are available on the desktop of the computer. A MS Word format version of locally written instructions is here.

The program for the instrument can convert data to text files which can be opened in Microsoft Excel or other programs. Most users transfer data from the computer with a USB flash drive, but can also copy data on to a floppy drive, CD or print it. Users can also load an analysis program on their own computer. The computer is not connected to the university network. The instrument is in room 1074, Jordan Hall. Contact John Shannon ph. 434.243.9399