Effect of MALDI Matrices on Lipid Analyses of Biological Tissues Using MALDI-2 Post-Ionization Mass Spectrometry

2020 ◽  
Author(s):  
Josiah McMillen ◽  
jarod Fincher ◽  
Dustin R. Klein ◽  
Jeffrey Spraggins ◽  
Richard M. Caprioli
Keyword(s):  
Mass Spectrometry ◽  
Neutral Lipids ◽  
Rat Kidney ◽  
Kidney Tissue ◽  
Biological Tissues ◽  
Intensity Increase ◽  
Ionization Mass ◽  
Tissue Mass ◽  
Lipid Signal ◽  
Tissue Homogenates

<p>Matrix-assisted laser desorption/ionization imaging mass spectrometry (MALDI IMS) allows for highly multiplexed, untargeted detection of many hundreds of analytes from tissue. Recently, laser post-ionization (MALDI-2) has been developed for increased ion yield and sensitivity for lipid IMS. However, the dependence of MALDI-2 performance on the various lipid classes is largely unknown. To understand the effect of the applied matrix on MALDI-2 analysis of lipids, samples including an equimolar lipid standard mixture, various tissue homogenates, and intact rat kidney tissue sections were analyzed using the following matrices: α-cyano-4-hydroxycinnamic acid (CHCA), 2’,5’-dihydroxyacetophenone (DHA), 2’,5’-dihydroxybenzoic acid (DHB), and norharmane (NOR). Lipid signal enhancement of protonated species using MALDI-2 technology varied based on the matrix used. Although signal improvements were observed for all matrices, the most dramatic effects using MALDI-2 were observed using NOR and DHB. For lipid standards analyzed by MALDI-2, NOR provided the broadest coverage, enabling the detection of all 13 protonated standards, including non-polar lipids, whereas DHB gave less coverage but gave the highest signal increase for those lipids recorded. With respect to tissue homogenates and rat kidney tissue, mass spectra were compared and showed that the number and intensity of neutral lipids tentatively identified with MALDI-2 using NOR increased significantly (e.g. 5-fold intensity increase for triacylglycerol). In the cases of DHB with MALDI-2, the number of protonated lipids identified from tissue homogenates doubled with 152 on average compared to 76 with MALDI alone. High spatial resolution imaging (~20 µm) of rat kidney tissue showed similar results using DHB with 125 lipids tentatively identified from MALDI-2 spectra versus just 72 using standard MALDI. From the four matrices tested, NOR provided the greatest increase in sensitivity for neutral lipids (triacylglycerol, diacylglycerol, monoacylglycerol, cholesterol ester) and DHB provided the highest overall number of lipids detected using MALDI-2 technology. </p>

Effect of MALDI Matrices on Lipid Analyses of Biological Tissues Using MALDI-2 Post-Ionization Mass Spectrometry

2020 ◽  
Author(s):  
Josiah McMillen ◽  
jarod Fincher ◽  
Dustin R. Klein ◽  
Jeffrey Spraggins ◽  
Richard M. Caprioli
Keyword(s):  
Mass Spectrometry ◽  
Neutral Lipids ◽  
Rat Kidney ◽  
Kidney Tissue ◽  
Biological Tissues ◽  
Intensity Increase ◽  
Ionization Mass ◽  
Tissue Mass ◽  
Lipid Signal ◽  
Tissue Homogenates

<p>Matrix-assisted laser desorption/ionization imaging mass spectrometry (MALDI IMS) allows for highly multiplexed, untargeted detection of many hundreds of analytes from tissue. Recently, laser post-ionization (MALDI-2) has been developed for increased ion yield and sensitivity for lipid IMS. However, the dependence of MALDI-2 performance on the various lipid classes is largely unknown. To understand the effect of the applied matrix on MALDI-2 analysis of lipids, samples including an equimolar lipid standard mixture, various tissue homogenates, and intact rat kidney tissue sections were analyzed using the following matrices: α-cyano-4-hydroxycinnamic acid (CHCA), 2’,5’-dihydroxyacetophenone (DHA), 2’,5’-dihydroxybenzoic acid (DHB), and norharmane (NOR). Lipid signal enhancement of protonated species using MALDI-2 technology varied based on the matrix used. Although signal improvements were observed for all matrices, the most dramatic effects using MALDI-2 were observed using NOR and DHB. For lipid standards analyzed by MALDI-2, NOR provided the broadest coverage, enabling the detection of all 13 protonated standards, including non-polar lipids, whereas DHB gave less coverage but gave the highest signal increase for those lipids recorded. With respect to tissue homogenates and rat kidney tissue, mass spectra were compared and showed that the number and intensity of neutral lipids tentatively identified with MALDI-2 using NOR increased significantly (e.g. 5-fold intensity increase for triacylglycerol). In the cases of DHB with MALDI-2, the number of protonated lipids identified from tissue homogenates doubled with 152 on average compared to 76 with MALDI alone. High spatial resolution imaging (~20 µm) of rat kidney tissue showed similar results using DHB with 125 lipids tentatively identified from MALDI-2 spectra versus just 72 using standard MALDI. From the four matrices tested, NOR provided the greatest increase in sensitivity for neutral lipids (triacylglycerol, diacylglycerol, monoacylglycerol, cholesterol ester) and DHB provided the highest overall number of lipids detected using MALDI-2 technology. </p>

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

2021 ◽  
Author(s):  
Hirofumi Enomoto
Keyword(s):  
Mass Spectrometry ◽  
Electrospray Ionization ◽  
Electrospray Ionization Mass Spectrometry ◽  
Mass Spectrometry Imaging ◽  
Desorption Electrospray Ionization ◽  
Biological Tissues ◽  
Ionization Mass Spectrometry ◽  
High Water Content ◽  
Ionization Mass ◽  
Adhesive Film

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.

Identification of Biological Tissues by Rapid Evaporative Ionization Mass Spectrometry

2010 ◽  
Vol 82 (17) ◽  
pp. 7343-7350 ◽  
Author(s):  
Julia Balog ◽  
Tamas Szaniszlo ◽  
Karl-Christian Schaefer ◽  
Julia Denes ◽  
Antal Lopata ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Biological Tissues ◽  
Ionization Mass Spectrometry ◽  
Ionization Mass

scholarly journals Identification of some Neutral Lipids of Thiobacillus Thioparus Using Gas Chromatography-Chemical Ionization Mass Spectrometry

1980 ◽  
Vol 33 (6) ◽  
pp. 737 ◽  
Author(s):  
RK Christopher ◽  
AM Duffield ◽  
BJ Ralph
Keyword(s):  
Mass Spectrometry ◽  
Chemical Ionization ◽  
Neutral Lipids ◽  
Lipid Fraction ◽  
Ethyl Esters ◽  
Ionization Mass Spectrometry ◽  
Chemical Ionization Mass Spectrometry ◽  
Ionization Mass ◽  
Thiobacillus Thioparus ◽  
Long Chain

The neutral lipid fraction of two strains of T. thioparus was examined using gas chromatographychemical ionization mass spectrometry. Both strains were found to produce fatty acid ethyl esters, long-chain alcohols and. wax esters. In addition, one strain produced substantial quantities of squalene, although no sterols or triterpenoids could be detected. However, in the second strain, although squalene was present at greatly reduced levels, cholesterol, lanosteryl acetate and 24,25-dihydrolanosteryl acetate were identified.

Sign in / Sign up

Export Citation Format

Share Document