Dear colleagues,

WG 4 of ARBRE-MOBIEU (Optimization of Data Quality) is setting up a benchmarking study on circular dichroism (CD) spectroscopy under the lead of Dr. Nikola Chmel (University of Warwick, UK), aiming to improve the quality of CD data. In order to maximize the outcome of the study we ask for your active support by participating in the study.

A pilot CD study has been conducted previously (in 2014 and 2015, involving eight labs) in order to give an overview of the present state of CD data quality across selected laboratories and a range of instruments across the network. It became apparent, even in such a small scale study, that there were significant differences in quality of the data recorded in different labs. Various issues were identified (e.g. intensity calibration, wavelength calibration, baseline drift), indicating that there is a need for a broader study within the ARBRE-MOBIEU community yielding a better picture of CD data quality and to take steps to improve the data quality and standardisation across the network. The follow-up study, starting on May, 30^th 2017, is intended to allow us a much more in-depth analysis of the issues around standardisation and calibration of the CD instrumentation as well as to introduce good practice through distribution of standard operating procedures (SOP) allowing for better comparability of CD data from different labs and instruments.

Time frame of the CD benchmarking study:

27^th May 2017 – deadline for CD benchmarking study sign up
30^th May – 2^nd June 2017 – distribution of samples and SOPs to the participating labs
June – July 2017 – data collection in the participating labs
14^th August 2017 – deadline for the return of samples and data to Warwick, UK
August – September 2017 – re-measurement of returned samples at Warwick, UK, data analysis

Format of the study:

Each of the participating labs will be sent 4 samples (1 sample of protein, 2 enantiomers of CD standard and a blank). Each lab will be asked to perform the following measurements on all samples:

• using the lab’s own  SOP
• using the supplied SOP
• provide recent (less than 7 days) calibration data for wavelength (e.g. Ho, ammonia, etc) and intensity (e.g. ACS)
• if no recent calibration data is available, the lab will be asked to check the calibration instrument using the lab’s own SOP or the supplied SOP
• samples need to be re-measured after calibration, if required.

If you are interested in participating in the CD benchmarking study please sign up using the form below before May, 27^th 2017:

http://warwick.ac.uk/nikolachmel/cdsurvey

If you have any questions about the project please contact Dr. Nikola Chmel ([email protected]).

Project lead: Dr. Nikola Chmel, Department of Chemistry, University of Warwick, UK.

Best regards,

Stefan Knauer (co-leader of WG4)