DESI imaging mass spectrometry on liver tissue
Presha Rajbhandari, Brent R. Stockwell, Brent R Stockwell
Abstract
Acquire DESI imaging mass spectrometry data on liver tissue sections at 40µm spatial resolution - to assess distribution of lipids and metabolites within the tissue.
Steps
Perform mass calibration of the instrument using Sodium formate and ion mobility using CCS Major Mix using electrospray ionization source.
Equipment
| Value | Label |
|---|---|
| Synapt G2-Si | NAME |
| Mass Spectrometer | TYPE |
| Waters | BRAND |
| 176003191 | SKU |
| http://www.waters.com/waters/home.htm?locale=en_DK | LINK |
Prepare spray solvent: 98:2 methanol:water with 0.1% formic acid and 20pg/µl leucine-enkephalin as lockmass
Fill the syringe and start the flow at 1.5µl/min
Set the DESI sprayer angle of 75°, nebulizing gas (N2) pressure of 0.3 PSLM
Dry the sample slide with tissue section in a vacuum desiccator for 10 minutes
Set the sprayer distance from the slide and the inlet tube and optimize signal intensity on a spare tissue section
Mark the corners of the slide with a colored marker pen and scan the slide
Place the slides on the DESI slide holder
Open HDI Imaging software (Waters Corp.) and import the slide image
Select the instrument type, slide holder in use, and mark the slide corners to define image coordinates
Define the m/z range, polarity and analyzer mode
Define the region of interest to image, pixel size and scan rate and export the experiment file
Load the samples on Masslynx software and start acquisition using appropriate data acquisition parameters on MS tune page
