text: While the first reports of its use dated to 1980, it was a further two decades before the technique of SRCD took off largely due to the work of Bonnie Wallace at Birkbeck College, University of London.  From around 2000, her aims in the field focused on both enhancing the collection of quality data through technical improvements, and on demonstrating "proof-of-principle" application studies, illustrating the novel information that SRCD offers. The construction on the Synchrotron Radiation Source (SRS) of the CD12 beamline at Daresbury Laboratory, opened in 2005 under the auspices of the Centre for Protein and Membrane Structure and Dynamics (CPMSD) of which Wallace was the Director, represented the first of the new, dedicated, second-generation SRCD beamlines.  It was quickly identified that the high photon flux from CD12 was causing denaturation of the protein sample but that this was resolvable by reducing the sample area being irradiated. Later studies have identified the flux threshold limits that induce SRCD protein denaturation.  The input from the Wallace lab to the early years of SRCD development also included the introduction of calibration and standardization of SRCD and cCD spectrophotometers, the creation of software to process the spectral data using CDtool, and CDtoolX, and to analyse the data using DichroWeb, and the generation of reference data sets of proteins to support these data analyses.  Additionally, her lab produced sample cells with reduced pathlengths, and using material, (CaF), transparent to VUV radiation which significantly enhanced the collection of data into the SRCD lower wavelength regions.
  New SRCD beamlines were constructed on various synchrotrons around the world.   ring, in the Department of Physics and Astronomy of Aarhus University in Denmark, became a dedicated second-generation synchrotron in 2005.  Ultimately this ring had two SRCD beamlines, [https://www.isa.au.dk/facilities/astrid/beamlines/uv1/uv1.asp UV1] and [https://www.isa.au.dk/facilities/astrid/beamlines/cd1/cd1.asp CD1], which migrated to the new third-generation ring, ASTRID2, in 2013/14, as [https://www.isa.au.dk/facilities/astrid2/beamlines/AU-uv/AU-uv.asp AU-UV] and [https://www.isa.au.dk/facilities/astrid2/beamlines/AU-cd/AU-cd.asp AU-CD]. SOLEIL synchrotron, near Paris, France, commissioned a dedicated SRCD beamline, [https://www.synchrotron-soleil.fr/en/beamlines/disco DISCO], around 2005.  At Hiroshima Synchrotron Radiation Center, also known as HiSOR, a VUVCD beamline was constructed over the same period, while a little later in 2009, an SRCD beamline was commissioned in Beijing, China.  This particular beamline is unique in that the synchrotron which acts as its light source is also the electron carrying ring of the Beijing Electron Positron Collider.  The SRS closed in 2008 being superseded in the UK by the Diamond Light Source on which an SRCD beamline opened for use in 2010.  With the SRS closure the CD12 SRCD beamline was moved to, and installed on, the ANKA Synchrotron Radiation Facility, (now called [https://www.ibpt.kit.edu/kara.php KARA]), part of Karlsruhe Institute of Technology (KIT), in Karlsruhe, Germany.  This beamline opened for users in 2011 but was closed in 2021.  Currently under construction (as of June 2023) on the Sirius synchrotron light source in Campinas, Brazil, is a new SRCD beamline,  CEDRO.