Size-Exclusion Chromatography (SEC)

A fast and sensitive SEC technique incorporating a wide pore stationary phase with fluorescence detection, and its benefits, are described.

Bryan Troxell and other StrideBio scientists used size-exclusion chromatography with UV and multiangle light scattering (SEC-MALS) to measure changes in different viruses.

The purpose of this short tutorial article is to review the terms and official nomenclatures for size-exclusion separations and to provide some guidance and recommendations for practicing chromatographers. The interconversion between the different metrics is explained and some examples are presented.

Reliable calibration curves in the low molar mass region can be obtained when using the elution volumes of all separated oligomers of low molar mass standards on high resolution columns. This article explains how to do this.

Technological limitations have made it difficult for scientists to identify oligonucleotide aggregates. This can pose challenges when finding techniques to reliably analyze size variants for large nucleic acids and lipid nanoparticles (LNPs).

Alena Kubatova, a professor in the Department of Chemistry at the University of North Dakota, in Grand Forks, North Dakota, is exploring new approaches in characterizing lignin, to understand its structural complexities and how these methods can help improve processing in biorefineries. LCGC spoke to Kubatova to discuss her recent research in understanding the chemistry of lignin.

In a new study, nucleic acid and LNP aggregation is examined using prototype ultrawide pore size exclusion chromatography (SEC) columns with low adsorption capabilities.

How to overcome calibration issues in GPC/SEC using DMF and DMAc.

This instalment of “Column Watch” presents many of the highlighted topics and trends observed at this exceptionally well-run symposium.

How do you judge the potential success of separating two polymers using GPC/SEC?

The two-dimensional liquid chromatography (2D-LC) separations were supplemented by the use of capillary-channeled polymer (C-CP) fiber columns.

This article details a recent experiment that demonstrates how nonspecific interactions can be prevented by using metal-free or low adsorption flow paths.

Characterizing lipid nanoparticles (LNPs) is a developing delivery modality in biotherapeutic analysis. We address some of the current challenges and opportunities in this field, including an examination of the most common tools used to characterize LNPs.

The latest developments and challenges of using liquid chromatography (LC) for copolymer analysis are discussed.

What parameters can influence an siRNA separation?

Determining a theoretical number of plates is an effective tool to ensure that the column is still applicable for the desired separation.

Determination of molar mass distributions and the molar mass averages derived therefrom are the main objectives of gel permeation chromatography/size-exclusion chromatography (GPC/SEC) analysis. But what is the meaning of these averages and how are they influenced by the setting of baselines and integration limits? This instalment of Tips and Tricks in GPC/SEC will try to provide a better understanding.

This installment of Tips & Tricks will provide some helpful pointers to keep your GPC/SEC system in good shape.

The state of protein-derived self-associated, aggregated, and fragmented impurities in therapeutics are critical quality attributes (CQAs) and are widely monitored using non-denaturing size-exclusion chromatography (SEC).

Developing and building a talent base in macromolecular separations should be a priority for employers. Here’s why.

What experimental details need to be considered when analyzing PEGs?

In 2015, the American Chemical Society’s Committee on Professional Training added a requirement to the ACS degree certification program that undergraduates learn about macromolecules, supramolecular aggregates, and nanomaterials (MSN). This requirement can be met by a specialized course in these topics, but many programs are also choosing the distribute these topics across the curriculum.

This exploration into commercially available light scattering detection systems for size-exclusion chromatography (SEC) emphasizes new technologies and will help users understand the options.

This instalment describes the interplay between column length, pore size distribution, and particle size to optimize GPC/SEC separations.

Hydrolyzed collagens (collagen peptides) are water-soluble products obtained by hydrolysis of natural proteins and used for dietary supplements. A simple GPC/SEC method is described for molar mass determination of collagen peptides, allowing reliable molar mass determination using ultraviolet (UV) detection.

Analytical size-exclusion chromatography (SEC) often suffers from several limitations. This article shows how some of these limitations can be partly (or even completely) resolved by a multi-angle light scattering (MALS) detector for the determination of molar mass distributions of synthetic and natural polymers.

How to create a calibration curve when no chemically-matching reference materials with narrow molar mass distribution are available.

A review of alternative approaches to narrow standard calibration.

Light scattering detectors are ideally suited for size-exclusion chromatography (SEC) because they provide the molecular weight and radius of gyration information of polymeric samples without column calibration. In this article, the fundamentals of light scattering as applied to SEC are introduced, with emphasis on the origin of the Rayleigh equation. This tutorial is geared to those new to the field or who already utilize light scattering and seek clarification regarding the multitude of equations associated with light scattering. Part X of this series will present a brief summary of commercially available light scattering instrumentation with emphasis on new detector technology. Owing to the complexity of data analysis and the many equations involved with light scattering measurements, part X will also include a glossary of principal symbols and a summary of relevant equations.