DLS is based on properties of macromolecules and small particles to elastically scattered electromagnetic waves. It is a direct, non-invasive and quick method to determine diffusion coefficients and to calculate the hydrodynamic radius and molecular weight. This information can be useful to judge whether or not and under which conditions a protein can be crystallized for structural investigation. The experiment shows in real time the aggregation state of a protein and how this is influenced by varying pH, temperature, time, buffer composition and addition of reagents, like metal ions or detergents, for instance.
Our core provides full training of instrument and software usage, protocols of start-up experiments, consulting in experimental design, support in data analysis, interpretation and presentation. For users more detailed information is available on DLS pages.
Example: Aggregation test of recombinant TEV protease.
Upper panel: shows the auto-correlation function
Lower panel:shows the size distribution of TEV at a selected time point (see also panel 3 in fig below)
Panel of eight consecutive measurements within a data set.
At constant temperature and buffer conditions a time-dependent change of the molecular radius was observed. As the protein aggregates, macromolecules move slower while the diffusion coefficient decreases and the molecular radius increases.
Specialty Protein Services Provided