Dynamic Light Scattering

Dynamic Light Scattering (DLS), also known as Photon Correlation Spectroscopy (PCS), is an analytical technique for determining the size and size distribution of particles suspended in fluids by analyzing the time-dependent intensity fluctuations of scattered laser light. Developed by Robert Pecora in 1964, DLS exploits the Brownian motion of particles: smaller particles move faster, causing faster intensity fluctuations; larger particles move slower, causing slower fluctuations. By correlating intensity over time, particle size is deduced. DLS is rapid, non-destructive, and requires minimal sample volume, making it the standard technique for characterizing nanoparticles, proteins, colloids, and emulsions.