DESI-MSI stands for Desorption Electrospray Ionization Mass Spectrometry Imaging. Think of it as molecular photography—this technique allows us to map the locations of chemicals, lipids, or drugs across the surface of biological samples like tissue slices. The best part? You only need to give us your tissues slides or frozen tissues, and don't need to label or treat your sample with dyes or radioactivity beforehand.
A gentle spray of charged liquid hits your sample’s surface, knocking molecules into the air and into a mass spectrometer via vacuum, where they're identified based on their precise weight and fragments. It’s like pressure-washing molecular secrets out of your tissue!
If your sample is relatively flat, we can probably scan it. This includes tissue slices, organ sections, plant leaves, microbial biofilms, and more.
We use the DESI source paired with the Waters SYNAPT XS mass spectrometer. This powerful system includes advanced features like ion mobility separation and MS/MS for deeper molecular insights.
We typically use mixtures of methanol and water or acetonitrile and water, sometimes with additives like formic acid and internal standards to improve ionization and mass measurements.
Yes. We can toggle between positive and negative ion modes to maximize the types of molecules we detect.
Where do drugs accumulate in tissues?
What lipids or metabolites are altered in diseased or mutant animal tissues?
Can we map tumor margins with metabolic changes?
What biomarkers distinguish healthy from diseased tissues?
We typically use frozen tissue sections, mounted onto regular glass slides. No matrix or coating is needed. Just dry and scan!
We typically achieve 20–200 micrometer resolution, but under optimal conditions, we can reach 10 micrometers. For ultra-fine work, nano-DESI can push spatial resolution into the nanometer range.
DESI-MSI excels at identifying small molecules, lipids, metabolites, peptides, and even drugs. Small proteins can be detected too, though with lower sensitivity.
Nope! DESI-MSI is label-free. It detects native molecules as they are, meaning there's no need for fluorescent dyes, isotopes, or antibodies.
No need for chemical matrices.
Works at room temperature (no vacuum or freezing required).
Quick and easy sample prep.
Non-destructive – use the same slide later for MSI data acquisition, H&E or immunohistochemistry.
No need for special slides – regular microscopic glass slides work just fine (75 mm x 25 mm or 76 mm x 26 mm).
We use HDI, MSiReader, SCiLS Lab, IMAGEREVEAL, METASPACE, and Cardinal (R package) to generate stunning molecular maps and statistics.
By default, DESI-MSI provides semi-quantitative data. But with proper standards and calibration, absolute quantification is possible.
Yes! By analyzing multiple tissue slices and stacking the data, we can reconstruct 3D molecular images of organs or tumors.
Absolutely. After DESI-MSI analysis, the same slide can be stained using H&E or immunostaining, and molecular and histological images can be merged for powerful comparisons.
Lower resolution than some other methods like MALDI (but nano-DESI helps).
Reduced sensitivity for large intact proteins.
Signal interference from complex tissue matrices.
Not all molecule can be detected. Test the system with standard compounds when possible.
DESI works in the open air, with no matrix or vacuum needed, and avoids background noise that can obscure small molecules. While MALDI is great for proteins and higher resolution, it requires more complex prep and expensive slides.