Nanospray desorption electrospray ionization mass spectrometry of untreated and treated probiotic Lactobacillus reuteri cells

Pneumatically Assisted Microfluidic Probe for Enhanced Mass Spectrometry Imaging Performance

A pneumatically assisted microfluidic probe (MFP) with two microfluidic channels has been developed for nanospray desorption electrospray ionization mass spectrometry imaging (nano-DESI MSI) of biological samples. This design simplifies the experimental setup, making it independent of the vacuum suction at the mass spectrometer inlet. The implementation of pneumatically assisted solvent flow through the probe enables stable, high solvent flow rates required to maintain a consistent liquid bridge during high-throughput MSI experiments. This approach addresses challenges associated with using MFP nano-DESI probes on mass spectrometers that have limited vacuum suction and the operation of MFPs with small microfluidic channels. We demonstrate the robustness of the pneumatically assisted MFP with 30 μm channels, which cannot be used for high-throughput MSI experiments without pneumatic assistance, by successfully imaging five mouse brain tissue sections without interruptions.

Liquid extraction surface analysis-mass spectrometry: An advanced and environment-friendly analytical tool in modern analysis

The Liquid Extraction Surface Analysis technique is a new high-throughput instrument for ambient mass spectrometry. The benefits of the Liquid Extraction Surface Analysis-Mass Spectrometry approach are the high throughput screening of samples and the absence of sample preparation. Liquid Extraction Surface Analysis-Mass Spectrometry also consumes less solvent for extraction, making it more environmentally friendly and there is no substrate restriction. It utilizes advanced instrumentation like the use of robotic pipettes, nanoelectrospray systems, electronspray ionization chips which makes it highly efficient. In recent years, Liquid Extraction Surface Analysis-Mass Spectrometry has seen widespread use in a variety of analytical fields including drug metabolite analysis, mapping drug distribution in tissues, protein and lipid characterization etc. In this review, we have summarized the basic working principles of the Liquid Extraction Surface Analysis-Mass Spectrometry approach in detail along with a detailed description of the recently reported applications in the analysis of proteins, lipids, drugs and foods. The investigated analytes along with detection methodologies and significant outcomes of various research reports have been presented with the help of tables. This tool has also been utilized in clinical investigations of biological fluids, fingerprint analysis and authentication of agarwood. This article is protected by copyright. All rights reserved.

Direct identification of bacterial and human proteins from infected wounds in living 3D skin models

Trauma is one of the leading causes of death in people under the age of 49 and complications due to wound infection are the primary cause of death in the first few days after injury. The ESKAPE pathogens are a group of bacteria that are a leading cause of hospital-acquired infections and a major concern in terms of antibiotic resistance. Here, we demonstrate a novel and highly accurate approach for the rapid identification of ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.) directly from infected wounds in 3D in vitro skin models. Wounded skin models were inoculated with bacteria and left to incubate. Bacterial proteins were identified within minutes, directly from the wound, by liquid extraction surface analysis mass spectrometry. This approach was able to distinguish closely related strains and, unlike genomic approaches, can be modified to provide dynamic information about pathogen behaviour at the wound site. In addition, since human skin proteins were also identified, this method offers the opportunity to analyse both host and pathogen biomarkers during wound infection in near real-time.