Analytical size exclusion chromatography coupled to absolute molar mass measurement by multi-angle light scattering (SEC-MALS) with a DAWN® multi-angle light scattering (MALS) detector demonstrates that each of the Yersinia pestis injectosome component proteins exhibits its predicted molar mass at 37°C, including purified monomeric and dimeric forms of LcrV.
Absolute characterization is performed by combining multi-angle light scattering with size exclusion chromatography (SEC-MALS) to determine molar mass, independently of elution standards.
Lignins exhibit significant absorbance of MALS laser light and consequent fluorescent radiation, present a significant challenge for most light scattering instruments. The DAWN® multi-angle light scattering (MALS) detector incorporates features to overcome these challenges and provide accurate molar mass determination. Read more here.
Size-exclusion chromatography in combination with multi-angle light scattering detection (SEC-MALS) provides an easy method to obtain the molar mass moments and distributions of the chitosan products in an absolute manner, free of molecular references. In this note, we describe the results for two chitosan samples analyzed by SEC-MALS.
Molecular weight is a critical quality attribute for polysaccharide-based vaccines, since it impacts immunogenicity. SEC-MALS is ideal for determining the molecular weight of a monovalent polysaccharide antigen but is not suitable for QC testing of a polyvalent vaccine. This note describes the validation of Rate Nephelometry (RN), a QC-appropriate technique, against SEC-MALS.
Sodium alginate is a food thickening agent that may be irradiated for sterilization. Changes in biopolymer molar mass and conformation due to irradiation are analyzed by SEC-MALS.
Determination of branching in amylopectin, an important property affecting viscosity, stiffness and thermo-mechanical performance, requires a fully-linear amylose analog. This analysis may be performed with the help of synthetic amyloses. This application note describes how synthetic amyloses from an enzymatic (phosphorolytic) reaction were checked for their linearity using SEC-MALS.
Chondroitin sulfate, a natural component of cartilage and connective tissue, is considered a helpful supplement for people suffering from arthritis. Different preparations of the product have different molecular properties, which are related in turn to therapeutic effectiveness. Such properties can be studied—and quantified—by light scattering analysis.
In this application note, two commercially available samples were analyzed by SEC coupled to a DAWN, Optilab, and ViscoStar. The MALS and RI signals were combined to determine absolute molecular weight, independently of elution time or column calibration. The ViscoStar was used in order to measure intrinsic viscosity (IV) and uncover additional information about the molecular structure of the analyzed polymers.
We have developed a SEC-MALS method and found it to be very suitable for the analysis of LMWHs. In order to cross-validate the SEC-MALS method against the EP method, we implemented the UV-RI method described in the EP monograph and compared the molecular weight results generated for LMWH using each analytical technique.
Protein nanocapsules are produced by ultrasound-induced crosslinking in a two-phase solution. The time evolution of measured average size reflects the separation of larger particles, which encapsulate larger proportions of organic solvent, to form a floating film, due to increased buoyancy.
