Flow Rate Determination of the Nanoflow Sheath Liquid CE-MS-Coupling Applying the nanoCEasy Interface.

In recent years, nanoflow sheath liquid (nanoSL) interfaces have been used more commonly for capillary electrophoresis-mass spectrometry (CE-MS) coupling due to their high sensitivity combined with flexibility in CE separation conditions. So far, the exact amount of sheath liquid (SL) and, thus, the dilution effect remain unknown due to the self-supplying type of the nanoSL interfaces. To quantify the SL flow rates, we present here an approach for the determination of the flow rate based on isotopically labeled standards using the nanoCEasy interface.

CE-MS and CE-MS/MS for the multiattribute analysis of monoclonal antibody variants at the subunit level.

The analysis of product-related substances and impurities is a critical step in the biopharmaceutical quality control of multiattribute monoclonal antibodies (mAbs), as posttranslational modifications or other variants can influence the product's biological activity. Many approaches are available for variant analysis; however, they are either variant-specific, mAb-specific, time-consuming, or require expensive equipment. Here, we present a generic capillary electrophoretic method based on a neutral-coated capillary which was coupled to mass spectrometry (MS) via the nanoCEasy interface for mAb variant analysis at the subunit level (enzymatically digested and reduced mAb).

CE-MS/MS and CE-timsTOF to separate and characterize intramolecular disulfide bridges of monoclonal antibody subunits and their application for the assessment of subunit reduction protocols.

Characterization at the subunit level enables detailed mass spectrometric characterization of posttranslational modifications (PTMs) of monoclonal antibodies (mAbs). The implemented reduction often leaves the intramolecular disulfide bridges intact. Here, we present a capillary electrophoretic (CE) method based on a neutral-coated capillary for the separation of immunoglobulin G-degrading enzyme of Streptococcus pyogenes (IdeS) digested and reduced mAb subunits followed by mass spectrometry (MS), MS/MS identification, and trapped ion mobility mass spectrometry (timsTOF).

Ion mobility in gas and liquid phases: How much orthogonality is obtained in capillary electrophoresis-ion mobility-mass spectrometry?

Ion mobility-mass spectrometry (IM-MS) is an ever-evolving tool to separate ions in the gas phase according to electrophoretic mobility with subsequent mass determination. CE is rarely coupled to IM-MS, possibly due to similar separation mechanisms based on electrophoretic mobility. Here, we investigate the orthogonality of CE and ion mobility (IM) by analyzing a complex peptide mixture (tryptic digest of HeLa proteins) with trapped ion mobility mass spectrometry (TIMS-MS).

Endoscopy in the Surgically Altered Bowel.

Improved utilization of surgical interventions to improve patient outcomes has led to an increased need to endoscopically evaluate and treat the bowel after surgery. The best outcomes are attained when the endoscopist coordinates with the surgeon, and in some cases the pathologist or radiologist to plan the procedure. Understanding the anatomy and pathology anticipated can allow planning for sedation, bowel cleanse and equipment needed.