ASMS (American Society for Mass Spectrometry) 2026

Abstract:
Wastewater monitoring offers a translational framework for real-time pathogen genomics and population-level health assessment. This seminar will describe integrated molecular and computational approaches for detecting and analyzing infectious disease threats, including SARS-CoV-2 variants, drug-resistant Candida auris, and sexually transmitted infections, as well as community-level substance use patterns directly from municipal wastewater. Leveraging whole-genome sequencing and multi-omics analyses of over 3,000 C. auris genomes, we identified emergent antifungal resistance variants in wastewater five months before clinical detection, enabling early public health intervention.

Title:
Direct Single-Cell Native Mass Spectrometry of Human Cells

Speaker:
Michiko Tajiri, Ph.D. Specially Appointed Assistant Professor, Yokohama City University

Abstract:
Native mass spectrometry (MS) enables the characterization of intact protein complexes while preserving non-covalent interactions. Here, we present a direct single-cell native MS approach that probes biomolecular and drug interactions in environments closely resembling the intracellular milieu by directly sampling individual cells without conventional purification or buffer exchange. Using this platform, we detect intact hemoglobin tetramers from single red blood cells and directly observe protein–drug complexes from single HEK293T cells overexpressing target proteins. Ongoing collaborative studies with Shimadzu Corporation are further advancing this technology toward endogenous protein interaction analysis using a next-generation multi-turn (MT) TOF MS system.

Title:
Per- and Polyfluoroalkyl Substances Distribution in Plant Tissues Determined with MALDI-Mass Spectrometry Imaging: Implications for Food Security and Phytoremediation

Speaker:
Tong Zhou - Graduate Student at Missouri S&T

Abstract:
To assess fate of Per- and polyfluoroalkyl substances (PFAS) in vascular plants, the uptake and translocation studies were completed by applying a matrix-assisted laser desorption ionization - mass spectrometry imaging (MALDI-MSI, supported by Shimadzu iMScope MALDI imaging system) to directly detect and map in a variety of plant tissues. PFAS are known to persist in many environments and accumulate in plants, impacting food security and also being of interest for potential phytoremediation. Here, a novel MALDI-time-of-flight (TOF) MS-based analytical method was developed to investigate the spatial distribution of four representative PFAS (PFBS, PFHxS, PFOS, and PFOA) in plant tissues. Poplar cuttings after the root formation were exposed to 1 ppm PFAS dosing solution for 14 days to be taken up by roots and translocated through the xylem to stems and leaves. The MALDI-MS images showed that the long-chain (C8) PFOS was predominantly retained at the root surface and at the Casparian strip, due to its hydrophobicity and affinity for the interfaces and selective barriers to transport into the food chain. In root, the average normalized intensities of PFOS (C8) were 6.4-, 2.7-, and 3.9-fold higher than PFBS (C4), PFHxS (C6), and PFOA (C8). In contrast, the short-chain (C4) PFBS was transported and accumulated mainly at leaf tip and distal margins, indicating higher mobility within the xylem stream and affinity for the leaf-air interface. Our findings contribute to a comprehensive understanding of the fate of PFAS in plants and reveal the mechanisms of root uptake, xylem translocation, tissue-specific accumulation, and, most importantly, the sub-tissue accumulation at vascular interfaces in the plants.