Typical applications are emulsions, micelles, polymers, proteins, nanoparticles or colloids.īased on the Brownian motion of dispersed particles, DLS can be used to determine the size of small particles in suspension or polymers in solution. What is Dynamic Light Scattering?ĭLS is the most common method of measurement for particle and molecular size analysis in the nanometer range. Samples are prepared in an appropriate liquid (typically water-based) at a concentrated level of 107 − 109 particles/ml and placed in the sample chamber which has a volume of 0.3 ml. The process of loading the sample into the cell and getting results can take as little as two to three minutes, and you can run batches of samples under the same conditions and directly compare results. NTA is a three to five step measurement process.

The ‘movie’ is stored at a rate of 30 frames per second and results may be outputted to a spreadsheet format. Polydisperse and multimodal systems are instantly recognisable and quantifiable, and when engaged in fluorescence mode, suitably labeled particles can be discriminated from the non-labeled background.Ī video camera captures a video file of the particles moving under Brownian motion and using the Stokes Einstein equation, calculates individual particle hydrodynamic diameter.

Enhanced by a near-perfect black background, particles appear individually as point-scatterers moving under Brownian motion. A monochromatic light source (laser beam) is passed through the sample chamber and picks up the particles in suspension in such a manner that they can be easily magnified. NTA visualises, measures and characterises virtually all nanoparticles (10 – 2000 nanometres). This is particularly important in making real time measurements such as in the study of protein aggregation, viral vaccines and exosomes/microvesicles. NTA makes practical and effective use of the properties of both light scattering and Brownian motion to gather the nanoparticle size distribution of samples in liquid suspension. Measurements take just minutes, allowing time-based changes and aggregation kinetics to be quantified. NTA provides real time monitoring of the subtle changes in the characteristics of particle populations with all analyses confirmed by visual validation. In an ideal scenario, you may want to consider a combination of both systems to take advantage of the complementary information the two techniques can provide. DLS will generally measure a wider size range than NTA, but NTA offers greater resolution than DLS (even with Multi-angle Dynamic Light Scattering). Nanoparticle Tracking Analysis (NTA) and Dynamic Light Scattering (DLS) are complementary techniques that offer different insights into your samples.

Dynamic light scattering ppt