Sophia Kenrick

This article presents two case studies regarding the characterization of protein-DNA complexes using two complementary multi-angle light scattering (MALS) techniques, namely size-exclusion chromatography (SEC–MALS) to determine absolute molar mass of each component, and composition-gradient MALS (CG–MALS) to quantify stoichiometry and affinity at binding sites in solution.

The functional properties of polymers, such as poly(lactic-co-glycolic acid) (PLGA), relevant to drug delivery and biomedical devices, are governed by the molecular properties of molar mass, composition, conformation, and branching. This article demonstrates how such polymers are fully characterized, quickly and absolutely, using gel permeation chromatography (GPC) with multi-angle light scattering (MALS) and online viscometry.

The degree and strength of self-association are critical quality attributes for insulin and its analogues. In this article we present the label-free determination of these quantities using composition-gradient multi-angle light scattering (CG-MALS), enabling the formulation of engineered insulin optimized for stability and efficacy.

Ultra-high performance liquid chromatography (UHPLC) enables fast, efficient separation of biomolec-ular samples. Compared to standard SEC, UHP-SEC provides improved resolution, higher throughput, less solvent and smaller sample consumption for analysis of precious biological samples.

The affinity and absolute stoichiometry of interactions between a DNA aptamer and a tetrameric target is quantified using CG-MALS is discussed.