Dynamic light scattering

Dynamic light scattering (DLS) is used to characterize particle size distributions and hydrodynamic sizes of particles and molecules ranging from 0.3 nm to 10 µm. Particle size is determined by measuring random changes in the intensity of light scattered from liquid dispersions. DLS is a nondestructive method.

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What is dynamic light scattering used for?

Dynamic light scattering is used to determine the size distribution of particles in solution or suspension. DLS is especially useful in nanotechnology applications, as it can detect particle sizes starting from 0.3–1 nm in diameter, depending on the equipment.

Other industries where DLS can be used for particle size distribution analysis include food and feed, cosmetics, construction materials, and pharmaceuticals, among many others. The technique can also be used to characterize the size of proteins, carbohydrates, and other macromolecules.

How does DLS analysis work?

The principle of DLS is based on the theory of Brownian motion, which states that small particles move faster than larger particles in a liquid or gas medium. During the analysis, the sample suspension is illuminated by a laser beam, leading to the laser light scattering in all directions as it hits the suspended particles. The intensity of the scattered light is affected by the physical properties of the particles, such as size and molecular weight. By measuring changes in intensity, DLS allows for the particle size distribution to be determined.

Suitable samples and sample preparation

DLS analysis is performed on liquid suspensions and dispersions, but solid particles may be analyzed after they have been dispersed in a suitable liquid. The typical detectable size range is 0.3 nm to 10 µm. If larger particles are present, they may affect the reliability of the results.

Strengths and limitations of dynamic light scattering

The main strength of DLS when compared with another routine particle size analysis method, laser diffraction (LD), is the ability to analyze sub-nanometer particles. Other advantages include a relatively simple sample preparation procedure and fastness of the analysis.

The main limitation of DLS is the assumption that particles are spherical, which may lead to uncertainties when determining the size of particles with a shape very different from that of a sphere. To obtain more precise information about the shape as well as the size of particles, it may be necessary to use other techniques, such as electron microscopy (TEM or SEM, depending on the required resolution).

Need an analysis?

Measurlabs offers particle size distribution analyses with DLS and several other techniques, including laser diffraction, nanoparticle tracking analysis, sieve analysis, particle size and shape analysis, and electron microscopy. Do not hesitate to contact our experts through the form below to discuss the testing options and to request a quote.

Suitable sample matrices

  • Liquids and suspensions
  • Inks and pigments
  • Microemulsions
  • Protein and polymer samples

Ideal uses of DLS analysis

  • Analyzing the hydrodynamic size and the size distribution of nanoparticles and molecules
  • Determining the size of proteins, polymers, micelles, carbohydrates and nanoparticles

Ask for an offer

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Answering the following questions helps us prepare an offer for you faster:

  • How many samples do you have and what is the sample material?

  • Do you have an idea about the approximate particle size range?

  • Do you know the shape of the particles (spherical, cylindrical, etc.)

  • Is the sample in solid form or is it a dispersion?

  • Do you have a recurring need for these tests? If yes, how often and for how many samples at a time?

Have questions or need help? Email us at or call +358 50 336 6128.

Frequently asked questions

What is DLS analysis commonly used for?

Dynamic light scattering is used to analyze hydrodynamic particle size and size distributions in several industries and research areas, including pharmaceuticals, cosmetics, nanotechnology, and biomedical sciences.

What are the limitations of DLS?

DLS analysis assumes particles to be spherical, which makes it less suitable for other shapes, such as rods and fibers.

What kind of samples can be analyzed with DLS?

DLS samples can be liquids or solids that can be suspended in a suitable solvent.

What is Measurlabs?

Measurlabs offers a variety of laboratory analyses for product developers and quality managers. We perform some of the analyses in our own lab, but mostly we outsource them to carefully selected partner laboratories. This way we can send each sample to the lab that is best suited for the purpose, and offer high-quality analyses with more than a thousand different methods to our clients.

How does the service work?

When you contact us through our contact form or by email, one of our specialists will take ownership of your case and answer your query. You get an offer with all the necessary details about the analysis, and can send your samples to the indicated address. We will then take care of sending your samples to the correct laboratories and write a clear report on the results for you.

How do I send my samples?

Samples are usually delivered to our laboratory via courier. Contact us for further details before sending samples.