Size Exclusion Chromatography – Multi-Angle Light Scattering (SEC-MALS) is a commonly used analytics for biologics in the determination of aggregation/oligomers, drug purity and fragment impurities. The technique combines the chromatographic separation by molecular size and the determination of absolute molar mass by light scattering without the limitations of MW standard calibration. The light scattering instrumentation also includes a Quasi- Elastic Light Scattering (QELS) and Refractive Index (RI) detectors for added versatility. SEC-MALS is typically employed during analytical characterization and early phase clinical trials of antibody and protein based therapeutics to support FDA IND submissions. More recent application includes analysis of extracellular vesicle (EV) – based therapeutics involving exosomes or microvesicles.