Publications

Tissue protein imaging at 1 μm laser spot diameter for high spatial resolution and high imaging speed using transmission geometry MALDI TOF MS

Zavalin et al. (2015). Analytical and Bioanalytical Chemistry. doi: 10.1007/s00216-015-8532-6

…de (ITO)-coated microscope glass slides were purchased from Delta Technologies (Stillwater, MN, USA). Carnoy’s fluid was prepared as a 6:3:1 solution of 100 % ethanol/chloroform/acetic acid. Fresh frozen mouse brain was purchased from Pel-Freez Biologicals (Rogers, AZ, USA). Sample preparation Tissue preparation, rinsing steps, and matrix spraying proto- cols were optimized to maximize ionizati

Abstract

We have achieved protein imaging mass spectrometry capabilities at sub-cellular spatial resolution and at high acquisition speed by integrating a transmission geometry ion source with time of flight mass spectrometry. The transmission geometry principle allowed us to achieve a 1-μm laser spot diameter on target. A minimal raster step size of the instrument was 2.5 μm. Use of 2,5-dihydroxyacetophenone robotically sprayed on top of a tissue sample as a matrix together with additional sample preparation steps resulted in single pixel mass spectra from mouse cerebellum tissue sections having more than 20 peaks in a range 3-22 kDa. Mass spectrometry images were acquired in a standard step raster microprobe mode at 5 pixels/s and in a continuous raster mode at 40 pixels/s.