Increased throughput and ultra-high mass resolution in DESI FT-ICR MS imaging through new-generation external data acquisition system and advanced data processing approaches

Abstract

Desorption electrospray ionisation-mass spectrometry imaging (DESI-MSI) is a powerful imaging technique for the analysis of complex surfaces. However, the often highly complex nature of biological samples is particularly challenging for MSI approaches, as options to appropriately address molecular complexity are limited. Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) offers superior mass accuracy and mass resolving power, but its moderate throughput inhibits broader application. Here we demonstrate the dramatic gains in mass resolution and/or throughput of DESI-MSI on an FT-ICR MS by developing and implementing a sophisticated data acquisition and data processing pipeline. The presented pipeline integrates, for the first time, parallel ion accumulation and detection, post-processing absorption mode Fourier transform and pixel-by-pixel internal re-calibration. To achieve that, first, we developed and coupled an external high-performance data acquisition system to an FT-ICR MS instrument to record the time-domain signals (transients) in parallel with the instrument’s built-in electronics. The recorded transients were then processed by the in-house developed computationally-efficient data processing and data analysis software. Importantly, the described pipeline is shown to be applicable even to extremely large, up to 1 TB, imaging datasets. Overall, this approach provides improved analytical figures of merits such as: (i) enhanced mass resolution at no cost in experimental time; and (ii) up to 4-fold higher throughput while maintaining a constant mass resolution. Using this approach, we not only demonstrate the record 1 million mass resolution for lipid imaging from brain tissue, but explicitly show such mass resolution is required to resolve the complexity of the lipidome.

Transient-Mediated Simulations of FTMS Isotopic Distributions and Mass Spectra to Guide Experiment Design and Data Analysis

“…Due to a specific peak-shape in the aFT full window case, the reported resolution gains in the literature may reach a 3-fold increase compared to the mFT mass spectra. [42][43][44] This result correlates with the data reported in Figure if FWHM is calculated from the corresponding level (9,000 resolution in the mFT mode versus 28,000 resolution in the aFT mode). Other apodization functions, e.g., an asymmetric full window Kilgour function, can further vary the apparent resolution.…”

Design of a biofluid-absorbing bioactive sandwich-structured Zn–Si bioceramic composite wound dressing for hair follicle regeneration and skin burn wound healing

“…Human hair follicles were obtained from the Plastic Surgery Hospital (Institute) of the Chinese Academy of Medical Sciences, which were isolated and cultured following a method described previously [ 50 ]. Isolated human hair follicles were cut from the bottom of the dermal papillary and cultured in William's E medium (Gibco) containing diluted ZnCS E culture medium extracts (1/16 dilution) and supplemented with 10 ng/mL hydrocortisone, 10 μg/mL insulin, 2 mM l -glutamine, and 1 × antibiotic/antimycotic solution at 37 °C in a 5% CO 2 atmosphere.…”

Mass spectrometry imaging as a potential technique for diagnostic of Huanglongbing disease using fast and simple sample preparation

“…Healthy, PCR-negative sweet orange nursery trees were used as controls, with Ct values above the threshold limit and most often with undetectable fluorescence in qPCR analysis 37 (data not shown), while C Las-infected samples had average Ct values of 20.9–23.9 for the asymptomatic leaves and Ct 19.1–21.6 for symptomatic leaves. It is possible to extract data using a leaf tissue surface with the size ranging to millimeter to centimeters and a scan time/pixel about 0.96–1.6 s 52 – 54 , which makes MSI a potential diagnostic tool to be implemented for a real-time detection of HLB in the field. Different leaf regions were fixed on the surface of a plate (Fig.…”