Dynamic Light Scattering (DLS)

Dynamic light scattering (DLS) is an indirect, high-throughput method for measuring the sizes – by hydrodynamic diameter (HDD) – of particles in a solution.

Strengths

• Fast, automated analysis = rapid results
• Accepts low sample concentrations
• Provides overall particle size distribution
• Works well with a wide range of particle sizes
• Nondestructive analysis

Limitations

• Does not provide particle shape information for irregular geometries
• Heavy particles can sometimes sediment, causing artifacts
• Bigger particles are higher-weighted in the raw intensity distribution

Learn More

Example Outputs Instruments Used How DLS Works

• Particle Diameter Range: 0.3 nm to 10 µm
• Minimum Sample Volume: 50 µL for particle size analysis
• Maximum Concentration: approximately 50% m/v (depends on sample)

Particles suspended in a liquid are constantly undergoing random Brownian motion, and their size directly affects their speed: smaller particles move faster than larger ones.

When a laser light source is applied to an aqueous sample of particles in solution, it scatters around them as it passes. The scattered light is detected and recorded at some pre-defined angles and the time-dependence of changes in the scattered intensity profiles can be correlated to the particles’ speed, and therefore to their average size and distribution throughout the system.

Plots of the relative frequency of distinct particle sizes and speeds can then be generated for subsequent analysis.