MS-IMS (MALDI-IMAGING)? Protein Chemistry/Proteomics and Peptide Synthesis and Array Unit Biomedicum Helsinki and Haartman Institute E-Mail: marc.baumann@helsinki.fi (http://research.med.helsinki.fi/corefacilities/proteinchem)
MALDI mass spectrometric imaging of biological tissue sections Tatiana C. Rohner, Dieter Staab and Markus Stoeckli Novartis Institutes for BioMedical Research, Novartis Pharma AG, Lichtstrasse 35, CH- 4002 Basel, Switzerland Mechanisms of Ageing and Development Mechanisms of Ageing and Development Volume 126, Issue 1, January 2005, Pages 177-185
Image (tissue, cell, bacteria, virus...) Scanning with a mass spectrometer
Definition MS is an analysis technique to determine by means of a mass spectrometer the molecule mass of free ions in high vacuum
MALDI Principles Mix analytes with excess matrix compound to crystallize (1:1000 1000 or 10 000) Matrix absorbs at the same laser wave length (commercially available N2- laser@337nm, YAG laser @355nm, infrared Er-YAG@2.94um) Short waved laser pulses
MALDI-TOF/TOF for LID-LIFT and high energy CID-LIFT Precursor Ion Selector LIFT Target CID cell (e.g. Argon) Potential Profile during LIFT LIFT
Tissue slide for IMS-MS
100µm raster step
Definitions: MALDI Imaging g (MALDI-IMS)(MS-IMS) ) A technique for analyzing the spatial arrangement of proteins, peptides, lipids, and small molecules in biological tissues A protein profiling technique which enables the direct sampling of histological section A technology that utilizes MALDI MS to map molecules of interest in thin tissue sections Potentially can deliver highly parallel, multiplexed data on the specific localization of molecular ions in tissue samples directly, and to measure and map the variations of these ions during development and disease progression or treatment
Principles Tissue section (mouse brain) on y Acquisitio 12mm Acquisition x Ion intensity 2,000 15,000 30,000 m/z A laser is rastered over a defined area while acquiring a complete mass spectrum from each position, resulting in molecular images for multiple analytes Cornett, et al., Nature Methods 2007
IMS workflow Stoeckli, M, et al., Analytical Biochemistry 2002
Benefits of MALDI-MSI Analysis of entire sample in one reading Previous knowledge of molecular composition is not necessary Allows for investigation of disease formation, progression, and treatment www.maldi-msi.org
Targeted labeling MS imaging i advantages No labeling required Biomolecules are functionally unmodified Label free imaging Image biomolecular modifications PTM s, Metabolites Detailed dinformation i on molecular identity Large scope of different elements and molecules
IMS vs. histochemical stain
Imaging MS applications Drug administration and detection
m/z 381 New Phytologist (2007) 173 : 438 444 m/z 543 m/z 705
Reconstruction of the Carbohydrate moiety Of WHEAT (Triticum aestivum)
Collection and storage of samples Embedding Tissue preparation and matrix application Section mounting Fixed versus fresh tissue Heeren RMA, USA
Tissue preparation and matrix application Heating 1-5 min Rapid Heating=treatment untreated Slow warming
Sample pretreatment prior to matrix application Tissue thickness 10-20 um On tissue digestion (spot and spray)
2D- IMS-MS for protein identification Peptide digestion on the membrane (identification of the proteins) Direct trypsin spraying; (Jardin-Mathé et al., 2008)
Comparing Regions of interest Control vs. patient
Matrix application methods
Matrix Application Matrix application is vital for quality image resolution Must contact sample as fine, liquid mist Current procedure involves manual application with airbrush 100 t t 100µm raster step Barrett-Wilt, G., USA
Home made spray device 1. Automatic Spray Gun 2. Conveyor 3. DC Timing Motor 4. Integrated Polyethylene Box 4 2 3 1 www.buswire.ocr.wisc.edu
Nano spotter Bruker IMAGE-PREP With SPR
Special Applications
Immuno-MS-IMS Imaging of regions immunoreactive with anti-synaptophysin Ab in healthy human pancreas. (A) Localization of synaptophysin positive cells by TAMSIM. The monoclonal rabbit anti-synaptophysin is conjugated with the tag El 307 (498 m/z). The false color green points in the section show the presence of the tag El 307 and thus synaptophysin positive cells. (B) Classical IHC image with the anti-insulin Ab. The dark pink spots correspond to Langerhans islets and so the synaptophysin-positive cells. The distribution of synaptophysin positive cells in (A) is very similar to that in (B). Thiery, G., et al., Proteomics 2008
Whole animal IMS-MS Effect of rastering
Microchips on IMS
Imaging MS for studying analyte deposition in dried droplet methods Distribution of analytes / particles in dried droplet deposition is not even. Typical case: stronger deposition at edges (coffee droplet effect). Matrix-free ionization of peptides. 1 mm circle and square shaped spots Raster spacing 25 µm or 50 µm
Some preliminary results Angiotensin 2, 1 µl, 1 pmol 1 mm spot [A+H] + 2 mm spot [A+H] + 2 mm spot [A+K] +
Some preliminary results Angiotensin 2, 1 µl, 1 pmol 1 mm spot [A+H] + 2 mm spot [A+H] + Divider/concentrator spot
Bi3+ ion imaging of peptide array on ion-nims surface
Other use of... - Laser Capture MC of single cells - protein profiling directly from gels etc
1-DE Chip electrodes gel reservoir: 25x32x0.3/0.5 mm PMMA, silica sample inlet buffer reservoir gel reservoir water cooling standard real sample Running time 10 minutes
T 2-DE Chip
2DE Performance Native IEF and native PAGE 5 variants of hemoglobin ph 6.7-7.7 Native IEF and SDS-PAGE standard IEF proteins ph 3-10 Denatured IEF and SDS-PAGE HbA 2 HbF HbS GFAP protein variants expression differences in control and Alzheimer diseased patients ph 4-6 HbA 1c HbA control AD
DIOS-MS Desorption Ionization On Silicon (DIOS) Matrix Free IMS laser MS porous area sample
3D IMS-MS
Resolving power of an MS
IMS FT-ICR-MS (Fourier Transformation Ion Cyclotron Resonance MS) Sensitivity in the zmol range
IMS-MS combined with other technologies