Every point is illustrated by case studies, including a commercially available albumin, a small RNA virus isolated from plants, as well as four soluble proteins and a ribonucleoprotein assembly purified and characterized by students in the frame of their master degree. Variables like temperature, solvent viscosity, and inter-particle interactions may also influence particle size determination. To ensure reproducible quantitative data, attention should be paid to controlling the preparation and handling of proteins or assemblies because variations in the state of aggregation, induced by minor changes in experimental condition or technique, might compromise DLS results and affect protein activity. It reviews the basic concepts of light scattering measurements and addresses four critical aspects of the analysis and interpretation of DLS results. This article is written for graduate and undergraduate students with access to DLS and for faculty members who wish to incorporate DLS into a lab activity, a practical course or research. The first method applies a ‘best fit’ to the Correlation Function and the shape of that fit leads to a diffusion coefficient, an average size, and a size distribution.Dynamic light scattering (DLS) analyses are routinely used in biology laboratories to detect aggregates in macromolecular solutions, to determine the size of proteins, nucleic acids, and complexes or to monitor the binding of ligands. Size of particles and molecules in a size range 0.3nm to 10 microns using NIBS technology and Dynamic Light Scattering. To get from a Correlation Function to the stuff you really care about – data – two analysis methods are used. This is also why DLS is sometimes called photon correlation spectroscopy (PCS). How quickly particles go from high correlation to zero correlation tells you their average size. Graph these correlation values for a range of jumps of different durations and you get a Correlation Function (Figure 2). Most particles will be in totally different spots – and you now have zero correlation in the data between your starting point and your jump one second later. Now instead of a microsecond, jump forward a full second. In other words, they have a high correlation. Odds are good most particles haven’t moved around yet – so the light scattering hasn’t changed and the data from time zero and a microsecond later are about the same. Here’s how to think about analyzing light scattering data for DLS: pick a point in time – now jump forward a microsecond. Analyzing whether light intensity is changing fast or slow – that’s the secret sauce of DLS. Vice versa for larger ones because they are slower to move around. Since small particles zip around quickly, the intensity of light changes quickly. When the laser wavelength is much larger than the particles, you get equal amounts of light scattering in every direction – that’s why we use a 660 nm laser in our DLS systems.ĭLS can tell you a lot about the size of the particles in solution by measuring how rapidly that scattered light changes over time (Figure 1). Shine a laser on a solution of particles and you’ll get plenty of light scattering back out at you. Monoclonal antibodies & recombinant proteins.Ultrafiltration & Diafiltration (UF/DF).Differential Scanning Fluorimetry (DSF).Purification-free lentivirus and exosome characterization ExoView R200 – Purification-free lentivirus and exosome characterization.The unrivaled particle characterization and ID platform Hound – The unrivaled particle characterization and ID platform.The all-around configurable benchtop workflow solution Junior – The all-around configurable benchtop workflow solution.The only completely hands-free benchtop buffer exchange solution Unagi – The only completely hands-free benchtop buffer exchange solution.The first all-in-one biologics stability screening platform Uncle – The first all-in-one biologics stability screening platform.Honeybun – The most rapid viscometer out there.The one of a kind silicone thickness and distribution analyzer Bouncer – The one of a kind silicone thickness and distribution analyzer. ![]() The most customizable automated workflow solution Big Kahuna – The most customizable automated workflow solution.The ultimate automated buffer exchange solution Big Tuna – The ultimate automated buffer exchange solution.The next-gen protein and nucleic acid quantification system Lunatic – The next-gen protein and nucleic acid quantification system.Stunner – The ultimate gene therapy tool.
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