Widely used in biochemistry, biotechnology and pharmaceutical development, Dynamic Light Scattering (DLS) is popular wherever the size distributions of macromolecules and nanoparticles need to be measured quickly and easily.

Dynamic Light Scattering

Size distributions without fractionation

Dynamic Light Scattering (DLS) measures the translational diffusion coefficients D_t of nanoparticles and colloids in solution by quantifying dynamic fluctuations in scattered light. Sizes and size distributions, in turn, are calculated from the diffusion coefficients in terms of hydrodynamic radius R_h or hydrodynamic diameter d_h.

DLS is suitable for ensemble measurements ranging from R_h values of 0.2 nm up to 5,000 nm. Wyatt offers high-throughput, automated DLS as well as conventional, cuvette-based formats.

Applications of DLS

Here are just a few of the diverse applications supported by DLS:

Estimate populations of aggregates large and small, for small molecules, proteins or liposomes
Check quality of biomolecules prior to running costly analyses such as SPR or SANS
Analyze thermal stability and chemical denaturation, differentiating pure unfolding from aggregation
Determine sizes of metallic nanoparticles or quantum dots
Quantify self-assembly processes of polypeptides or DNA
Assess colloidal stability as a precursor to aggregation and precipitation
Measure viscosity of concentrated biotherapeutics with just a few microliters of solution

DLS analysis showing a protein monomer mixed with 50 nm particulates. The size resolution of unfractionated solutions is a factor of 3-5x in radius.

DLS determines size distributions without fractionation, providing polydispersity estimates as well as hydrodynamic radii.

Dynamic Light Scattering is also known as Quasi-Elastic Light Scattering (QELS) and Photon Correlation Spectroscopy (PCS).

Automated DLS

Low-volume, automated measurements performed directly in place in standard 96-, 384- or 1536-well microwell plates reveal new horizons for dynamic light scattering. Some of the high-throughput screening tasks accomplished with the DynaPro® Plate Reader include:

Quantifying type and degree of aggregation in hundreds of buffer conditions, important in formulation and crystallization studies
Pre-formulation of biotherapeutic candidates to evaluate developability
Assessment of buffer excipients and pH for colloidal stability using the diffusion interaction parameter k_D
Assessment of multiple formulations for thermal (conformational) stability using the melting temperature T_m
Screening compound libraries for inhibition or enhancement of protein-protein interactions
Integration of plate-based testing protocols with other kinds of plate readers

In addition, microwell-plate-based DLS is an attractive option for multi-user labs: with no costly quartz cuvettes to wash, each user can have an inexpensive, personal, disposable plate sufficient for hundreds of samples and no concern for cross-contamination with other experiments.

Melting/aggregation curve data and analyses for four proteins measured simultaneously, in triplicate, on the DynaPro Plate Reader.

Color-coded Results

Color-coded results of measurements of three proteins, four pH conditions and 6 concentrations, with five replicates per combination, in a 384 well plate. Total measurement time was < 1.5 hours.

Selected references

Afonin, K. A.; Kasprzak, W.; Bindewald, E.; Puppala, P. S.; Diehl, A. R.; Hall, K. T.; Kim, T. J.; Zimmermann, M. T.; Jernigan, R. L.; Jaeger, L.; Shapiro, B. A. Computational and experimental characterization of RNA cubic nanoscaffolds. Methods 2014, 67, 256-265.

Akiyama, S. Quality control of protein standards for molecular mass determinations by small-angle X-ray scattering. J. Appl. Crystallogr. 2010, 43, 237-243.

An, W.; Zhang, H.; Sun, L.; Hao, A.; Hao, J.; Xin, F. Reversible vesicles based on one and two head supramolecular cyclodextrin amphiphile induced by methanol. Carbohyd. Res. 2010, 345, 914-921.

Ferré-D'Amare, A. R.; Burley, S. K. Dynamic light scattering in evaluating crystallizability of macromolecules. Method. Enzymol. 1997, 276, 157-166.

Mohr, J.; Chuan, Y. P.; Wu, Y.; Lua, L. H. L.; Middelberg, A. P. J. Virus-like particle formulation optimization by miniaturized high-throughput screening. Methods 2013, 60, 248-256.

BIBLIOGRAPHIC SEARCH

Application notes

pH Effects on Stability and Homogeneity of Protein Complex

Thermal Stability as a Function of pH and Concentration

Protein Aggregates Analyzed by the DynaPro Plate Reader

Nanoparticles (NPs) and Biology

Non-Specific Small Molecule Aggregation

MORE APPLICATIONS

Instrumentation for DLS

DLS Cuvette
Automated DLS
On-Line DLS
Accessories
Software

Cuvette-based DLS Instrument

DynaPro® NanoStar® - With sample volumes as small as 1.25 µL and temperature control spanning -15°C to +150°C, the NanoStar goes above and beyond traditional cuvette-based DLS instruments. It offers an optimized static light scattering detector in parallel to the DLS detection system in order to determine true molar mass.
Automated DLS Instrument

DynaPro® Plate Reader - The only commercially available instrument that measures DLS and SLS, for size and molar mass, directly in situ in standard 96, 384 or 1536 microwell plates. Measures second virial coefficient A₂ and diffusion interaction parameter k_D. The non-perturbing DynaPro Plate Reader offers integration with robot liquid handlers and multi-technique plate-based assay protocols. Temperature-controlled over 4°C to 85°C. An integrated camera views each well to observe precipitation or turbidity as well as troubleshooting and diagnostics.

Mobius™ The Mobius is not only the most sensitive zeta potential detector available, it is also a top-of-the-line dynamic light scattering detector. The Mobius provides connectivity to an autosampler for hands off, multi-sample operation.
The Mobius is also the only mobility detector that measures dynamic light scattering (DLS) simultaneously with zeta potential, in the same scattering volume, to monitor potential sample degradation.
On-Line DLS Detector

WyattQELS™ - A dynamic light scattering (DLS) module which integrates into a DAWN, miniDAWN or microDAWN MALS detector to provide simultaneous DLS measurements in the same scattering volume.
Accessories

microCUVETTE - Allows static and/or dynamic light scattering measurements to be made in a quartz cuvette in a DAWN, requiring only 10 µL.

NanoFilter Kit - Makes it easy to filter, recover and refilter precious sample. This is especially useful when your total sample volumes are below 300 µL.
Software

ASTRA® - Our comprehensive software solution for MALS and DLS analysis in chromatography, FFF or batch mode. ASTRA is available in a 21CFR(11) compliant version and offers additional options such as particle analysis.

DYNAMICS® - Software for batch DLS measurements in the DynaPro and Mobius™ instruments, as well as molar mass and A₂ in the NanoStar and DynaPro Plate Reader and electrophoretic mobility in the Möbius. Calculates size and size distributions, and derives parameters such as the melting temperature T_m, the aggregation onset temperature T_agg and the diffusion interaction parameter k_D.