Fouling of virus filtration membranes by monoclonal antibody feeds with low aggregate content.

Membrane fouling by monoclonal antibodies (mAbs) is one of the main challenges in virus-filtration processes. Previous publications attributed membrane fouling to the presence of mAb aggregates in the solution, which block the membrane pores. This fouling mechanism can be solved by a prefilter; however, it was shown that there are mAbs that severely foul the membranes (reduce permeability by 90% and more) even after prefiltering the aggregates, while other mAbs foul the membrane weakly (reduce permeability by ~10% and less).

High Performance Anion Exchange and Hydrophilic Interaction Liquid Chromatography Approaches for Comprehensive Mass Spectrometry-Based Characterization of the N-Glycome of a Recombinant Human Erythropoietin.

Comprehensive characterization of the N-glycome of a therapeutic is challenging because glycans may harbor numerous modifications (e.g., phosphorylation, sulfation, sialic acids with possible O-acetylation).

In-depth analyses of native N-linked glycans facilitated by high-performance anion exchange chromatography-pulsed amperometric detection coupled to mass spectrometry.

Characterization of glycans present on glycoproteins has become of increasing importance due to their biological implications, such as protein folding, immunogenicity, cell-cell adhesion, clearance, receptor interactions, etc. In this study, the resolving power of high-performance anion exchange chromatography with pulsed amperometric detection (HPAE-PAD) was applied to glycan separations and coupled to mass spectrometry to characterize native glycans released from different glycoproteins. A new, rapid workflow generates glycans from 200 μg of glycoprotein supporting reliable and reproducible annotation by mass spectrometry (MS).

Microfluidic membrane suppressor module design and evaluation for capillary ion chromatography.

A microfluidic ion-suppression module for use in ion-exchange chromatography has been developed and evaluated. The device consists of an ion-exchange membrane clamped between two polymer chips featuring a 200×100μm (width×depth) eluent channel (l=60mm), and a 300×150μm regenerant channel (60mm), respectively. The suppression efficacy using a Nafion membrane was compared with that of a styrene-sulfonate grafted fluorinated ethylene propylene (FEP) membrane.

Using contemporary liquid chromatography theory and technology to improve capillary gradient ion-exchange separations.

The gradient-performance limits of capillary ion chromatography have been assessed at maximum system pressure (34.5 MPa) using capillary columns packed with 4.1 μm macroporous anion-exchange particles coated with 65 nm positively-charged nanobeads.

Performance evaluation of ion-exchange chromatography in capillary format.

The performance of a recently introduced capillary ion-exchange chromatography system was explored. Experiments were conducted in isocratic mode with a commercial capillary anion-exchange column (id = 0.4 mm, L = 15 cm) using a five-anion standard mixture.

Capillary ion chromatography at high pressure and temperature.

The application of high pressure and temperature in ion chromatography (IC) can significantly improve the efficiency and reduce the analysis time. In this work, the kinetic-performance limits of capillary IC columns with inner diameters of 400 μm packed with 4 and 7 μm macroporous anion-exchange particles were investigated employing a capillary ion-exchange instrument allowing column pressures up to 34 MPa and column temperatures up to 80 °C. Plate heights below 10 μm could be realized using capillary columns packed with 4 μm particles.

Reversed-phase monoliths prepared by UV polymerization of divinylbenzene.

Many different techniques have been developed to prepare monolithic materials specifically for chromatographic techniques. The two most popular polymerization techniques being thermal or via ultra violet (UV) light. Whereas thermal polymerization is easily employed for a whole variety of monomer and porogen systems, UV polymerization has been limited to methacrylate-based systems, and styrenic systems have been avoided due to their strong absorbance at low wavelengths.