Likewise, heavily glycosylated proteins cannot be represented by reference standards or common models for globular proteins, and so are not amenable to analysis by traditional techniques. Denaturing SDS-PAGE dissociates native oligomers and precludes their identification, while cross-linked mass spectroscopy can create oligomers that do not exist in solution. Membrane proteins solubilized with detergent are particularly difficult to analyze by traditional techniques or even by mass spectroscopy because of the surfactant micelle surrounding the protein. The only function of the SEC column is to separate molecules by size, while MALS determines molar mass of eluting proteins independently. That's because SEC-MALS constitutes a rigorous, first-principles analysis of molar mass that does not rely on retention time or calibration with reference molecules. Multi-angle light scattering coupled with SEC ( SEC-MALS) provides accurate molecular weight determination of proteins, oligomers and complexes, regardless of conformation or non-ideal column interactions. These techniques invoke assumptions of conformation and ideal matrix interactions that may fool scientists with ambiguous or completely incorrect results, leading to fundamentally inaccurate interpretation of their data for scientific publications. Molar mass is the key to identifying proteins, their oligomers or complexes, yet all too many protein researchers rely on simplistic, invalid analysis of molecular weight by SDS-PAGE or traditional size exclusion chromatography (SEC). Molecular charge of fragile biomolecules is determined by combining simultaneous electrophoretic mobility and size measurements in the Mobius ™ using DYNAMICS.

Rapid assessments of purity, aggregation and oligomerization may be made through size distributions via dynamic light scattering using a microwell-plate-based DynaPro ® Plate Reader or a DynaPro ® NanoStar ® microcuvette-based instrument and the DYNAMICS ® software.

The DAWN also combines with the Calypso ® composition-gradient system for the study of biomolecular interactions via CG-MALS and CALYPSO ™ software.

Protein sizes are determined by adding a WyattQELS ™ DLS module into the DAWN or miniDAWN.

The DAWN ® and miniDAWN ® multi-angle light scattering detectors interfaces with any SEC system for determination of absolute molar mass via SEC-MALS and ASTRA ® software.

Light scattering provides a simple and effective means for characterizing the essential biophysical properties of proteins: molar mass, size, charge, interactions, conjugation and conformation.

Proteins and related biomacromolecules are complex entities that exhibit fascinating behavior when interacting with other biomolecules.

Dynamic & Electrophoretic Light Scattering.

Dynamic light scattering ppt