Biological Scattering Tools

The following web-based applications are available for the planning and analysis of small angle scattering (SAS) experiments:-

1) BSLDC - (The Biomolecular neutron scattering length density calculator) - which determines the "match points" of biomolecules, specifically peptide / protein, DNA and RNA, in D2O : H2O mixtures or with increasing levels of deuteration. The calculator also provides a number of other parameters, including chemical composition, molecular weight (Mw), estimated volume (as a sum of the components) and an estimate of the forward (also called zero angle) intensity (I(0)) of the biomolecule. For more information please refer to the manual .

2) A Guinier analysis web tool - this web tool will upload reduced SAS data either as text, Csv or ATSAS files (in a 3 column (Q,I,Err) - 1 line header format - see the manual for further details). It then performs a Guinier plot on the data to allow the determination of the radius of the radius of gyration (Rg) and forward (zero angle) intensity (I(0)) of the sample It has been tested on the latest versions of Mozilla Firefox v28.0 and Google Chrome v34.0, it will not work on Microsoft Internet Explorer v10.0 due to it's current lack of support for HTML5. For more information please refer to the manual.

3) The EDNA Biosas pipeline - is available to generate "dummy atom models" (see Figure 1 - Right) through a web portal using the STFC HPC SCARF cluster. You must be a registered SCARF user and have requested access to the pipeline. For more information on using the pipeline please refer to the manual.

Figure 1 - Left - SAS data loaded into the Guinier web-tool displayed in Log (I) - q format. / Centre - The data plotted as a Guinier plot (ln I - q2). / Right - An example "dummy atom model" for monomeric green fluorescent protein aligned and overlaid onto the crystal structure (Pdb: 1EMA), created using the Dammif software from the ATSAS suite of programs. Also shown are the 10 Dammif models generated , which were averaged to give the final model.


ISIS Biology and Biomembranes page - provides information about the ISIS Biology group and available experimental facilities at ISIS.

2) ISIS is involved in CCP-SAS - a UK/US collaboration to develop new computational tools for the analysis of SAS data. For more information on the status of the project, please see the following website.

This webpage is maintained by Dr Daniel Myatt . Find information on the author here .