Adhesive film applications help to prepare strawberry fruit sections for desorption electrospray ionization-mass spectrometry imaging

ABSTRACT Desorption electrospray ionization-mass spectrometry imaging (DESI-MSI) is a powerful tool to analyze the distribution of metabolites in biological tissues. Cryosectioning of biological tissues is usually required prior to DESI-MSI, but it can be difficult for tissues that are fragile, hard, and have a high-water content. The Kawamoto method uses transparent adhesive films to prepare cryosections; however, its application for plant tissues, such as strawberry tissues, in DESI-MSI has not been verified. In this study, strawberry cryosections maintained original structures were prepared using adhesive film. Subsequently, numerous peaks were detected for the sections using the positive and negative ion modes of DESI-MSI. Several primary and specialized metabolites, such as amino acids, sugars, organic acids, and flavonoids, were identified and visualized. These results suggest the use of adhesive films when cryosectioning could improve DESI-MSI analysis of the metabolites in strawberry fruits and various tissues of other plant species. Graphical Abstract Graphical Abstract Strawberry cryosection using adhesive film (a) and desorption electrospray ionization-mass spectrometry imaging of the various metabolite ions (b).