Accelerating strain phenotyping with desorption electrospray ionization-imaging mass spectrometry and untargeted analysis of intact microbial colonies.

Reading and writing DNA were once the rate-limiting step in synthetic biology workflows. This has been replaced by the search for the optimal target sequences to produce systems with desired properties. Directed evolution and screening mutant libraries are proven technologies for isolating strains with enhanced performance whenever specialized assays are available for rapidly detecting a phenotype of interest.

Mass spectrometry and ion mobility study of poly(ethylene glycol)-based polyurethane oligomers.

Rationale: Commercial-grade polymer synthesis is performed via melt polymerization, which leads to polydispersion. The work reported herein provides a synthetic strategy to produce mono-dispersive polyurethane oligomers and an analytical strategy to distinguish these oligomers, providing chemists with the tools necessary to synthesize and identify specific polymer structures that exhibit a desired property.

Methods: Three isomeric poly(ethylene glycol)-polyurethane (PEG-PUR) oligomers were synthesized and analyzed via flow-injection ion mobility mass spectrometry (IM-MS).

Spatiochemically Profiling Microbial Interactions with Membrane Scaffolded Desorption Electrospray Ionization-Ion Mobility-Imaging Mass Spectrometry and Unsupervised Segmentation.

Imaging the inventory of microbial small molecule interactions provides important insights into microbial chemical ecology and human medicine. Herein we demonstrate a new method for enhanced detection and analysis of metabolites present in interspecies interactions of microorganisms on surfaces. We demonstrate that desorption electrospray ionization-imaging mass spectrometry (DESI-IMS) using microporous membrane scaffolds (MMS) enables enhanced spatiochemical analyses of interacting microbes among tested sample preparation techniques.

Chiral separation of diastereomers of the cyclic nonapeptides vasopressin and desmopressin by uniform field ion mobility mass spectrometry.

In this study ion mobility-mass spectrometry (IM-MS) is used to distinguish chiral diastereomers of the nonapeptides desmopressin and vasopressin. The differences in gas phase cross sectional area (ca. 2%) were sufficient to directly resolve the enantiomers present in a binary mixture.