Skip to main page content
Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2016 Mar;4(3):3-13.

The Need for Speed in Matrix-Assisted Laser Desorption/Ionization Imaging Mass Spectrometry

Affiliations
Free PMC article

The Need for Speed in Matrix-Assisted Laser Desorption/Ionization Imaging Mass Spectrometry

Boone M Prentice et al. Postdoc J. .
Free PMC article

Abstract

Imaging mass spectrometry (IMS) has emerged as a powerful analytical tool enabling the direct molecular mapping of many types of tissue. Specifically, matrix-assisted laser desorption/ ionization (MALDI) represents one of the most broadly applicable IMS technologies. In recent years, advances in solid state laser technology, mass spectrometry instrumentation, computer technology, and experimental methodology have produced IMS systems capable of unprecedented data acquisition speeds (>50 pixels/second). In applications of this technology, throughput is an important consideration when designing an IMS experiment. As IMS becomes more widely adopted, continual improvements in experimental setups will be important to address biologically and clinically relevant time scales.

Keywords: Imaging mass spectrometry; MALDI; TOF; high-speed imaging.

Figures

Figure 1
Figure 1. IMS workflow
a) Specimens are prepared for analysis by mounting thinly cut tissue sections onto slides. Matrix application is then performed via any number of methods prior to b) MALDI analysis. c) Mass spectra generated at each x, y position are then used to d) construct intensity map images for any single ion of interest. e) Analyte identification can be performed by one or a combination of several techniques.
Figure 2
Figure 2
A depiction of an IMS experiment showing that, given a defined circular tissue area (d=1.5 cm, represented by one cartoon brain image, images not shown to scale) and a 1 pixel/second acquisition speed, the amount of tissue that can be sampled in 12 hours is dependent upon the spatial resolution of the experiment. Percentages indicate the approximate proportion of one brain section that can be measured at the indicated spatial resolution.
Figure 3
Figure 3
A 39,073 pixel MALDI image of a coronal rat brain section was sampled at 50 μm spatial resolution and was acquired in approximately 45 minutes. a) An average mass spectrum of 100 pixels shows the various lipid ions that were detected. b) A scanned optical image shows the tissue section following MALDI matrix application. Ion images of nominal masses c) m/z 734 and d) m/z 778 are plotted as m/z 734.6±0.6 and m/z 778.6±0.6, respectively, and show differential localization in brain substructures.
Figure 4
Figure 4
A 644,134 pixel MALDI image of a transverse rat brain section was sampled at 20 μm spatial resolution and was acquired in approximately 345 minutes. a) An ion image of nominal mass m/z 770 depicts the entire brain. b) Ion images of nominal masses m/z 770, m/z 794, and m/z 885 are shown in an enlarged region of the cerebellum highlighted in (a) using the pink box and are plotted as m/z 770.6±0.5, 794.7±0.5 and m/z 885.6±0.5, respectively, using root mean square (RMS) normalization. c) A hematoxylin and eosin stain of the tissue section is performed following MALDI IMS analysis. d) The enlarged region of the cerebellum is highlighted in (c) using the black box.

Similar articles

See all similar articles

Cited by 3 articles

LinkOut - more resources

Feedback