Determination of chain conformation of polysaccharides using a SEC‐MALLS‐Vis

Abstract For polysaccharides, biological activity is associated with the chemical structure as well as the chain conformation. The chain conformation is conventionally derived from the scaling relationships between weight‐average molecular weight ( M w ) and intrinsic viscosity ([ η ]) or the radius of gyration ( R g ) or the translational diffusion coefficient ( D ). However, obtaining narrowly dispersed fractions for such analysis is required, which is often challenging and time‐consuming. This protocol presents an integrated method using the size‐exclusion chromatography coupled with multi‐angle laser light scattering and an online viscometer (SEC‐MALLS‐Vis), allowing simultaneous determination of M w , z‐average radius of gyration ( R g,z ), and [ η ], as well as establishing the scaling laws of R g,z ∼ M w and [ η ] ∼ M w to preliminarily classify the flexible and stiff chain conformation. Furthermore, by combining these data with polymer solution theory for linear polymers with or without short branches, the key chain conformation parameters of persistence length ( q ), chain diameter ( d ), and molar mass per contour length ( M L ) can be obtained for deducing the type of chain conformation such as random coil, single helix, double helix, triple helix, rod‐like shape, or wormlike chain conformation. This approach provides a rapid and comprehensive way to for characterizing chain conformation of polysaccharides and other biomacromolecules.