Application of maldi msi in lipid


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Application of Matrix assisted laser desorption mass spectrometry image in lipid research

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Application of maldi msi in lipid

  1. 1. Application of MALDI-MSI in Lipids Date: 100-12-27 Supervisor: Prof. Hui-Fen Wu Student: Hani Nasser Abdelhamid M.Sc student at NSYSU, Taiwan (ROC) Tutor at Assuit university, Egypt.
  2. 2. Outline Introduction -MALDI-TOF. -Lipids. Application I. Application II. Summary. Discussion and Questions.
  3. 3. Introduction Mass spectrometry components •Douglas A. Skoog, F James Holler, Stanley R. Crouch, Principles of Instrumental Analysis, six edition ,Thomson Higher Education 10 Davis Drivt' Belmont,p564.
  4. 4. Mass analyzer • Quadrupole analyzer. • Ion trap (IT) instruments, • time-of-flight (TOF), • Orbitrap . • Ion cyclotron resonance (ICR) mass analyzers. • ESI triple quadrupole (ESI-QQQ). • QTOF.
  5. 5. Matrix Assisted Laser Desorption Ionization MALDI Beate Fuchs Progress in Lipid Research 2010.49 ,450–475
  6. 6. Alexandra P. Kafkaa International Journal of Pharmaceutics 2011,417 70– 82 Matrix
  7. 7. The matrix MALDI TOF matrices should be: 1. embed and isolate analytes (e.g., by co-crystallization). 2. be soluble in analyte-compatible solvents. 3. vacuum-stable. 4. absorb the laser wavelength. 5. initiate co-desorption of analyte upon laser irradiation 6. promote analyte ionization .
  8. 8. Matrix Example Both choice of matrix and sample preparation have been shown to influence the nature of molecules that can be detected using MALDI TOF and the quality of the resulting data
  9. 9. Lipids • 50–60% of the constituents of cell membranes. • 20–25% of the Brain dry weight . Importance • provide energy for the body( lysosomes ). • Disorder of lipid distribution cause a lot of disease.
  10. 10. Wolman Disease, and Lysosomal acid lipase LAL deficiency .Cell death
  11. 11. Application I
  12. 12. The workflow scheme CH3 OH OH O OH OH OH O
  13. 13. Cryostat (Leica)
  14. 14. CH3 OH OH O OH OH OH O
  15. 15. 2,5 DHAP problem • Vaccum unstable. • heterogeneous crystallization. (a)2,5-DHBdeposition (c)2,5-DHB/3-AP deposition(b)2,6-DHAPdeposition 250µm 250µm 250µm 2,5 DHB problem • Vaccum stable. • heterogeneous crystallization.
  16. 16. (a) 2,5-DHB/ANI (b) 2,5-DHB/DANI (c) 2,5-DHB/DEANI (d) 2,5-DHB/Pyr (e) 2,5-DHB/3-AP  automatic microspotter 2,5-DHB/ANI (2,5-DHB/aniline), 2,5-DHB/DANI (2,5-DHB/N,N-dimethylaniline), 2,5-DHB/DEANI (2,5-DHB/N,N-diethylaniline), 2,5-DHB/Pyr (2,5-DHB/pyridine), 2,5-DHB/3-AP (2,5-DHB/3-acetylpyridine).
  17. 17. (a) 2,5-DHB/ANI (b) 2,5-DHB/DANI (c) 2,5-DHB/DEANI (d) 2,5-DHB/Pyr (e) 2,5-DHB/3-AP MALDI(-) .All LIM are same
  18. 18. MALDI(+)
  19. 19. Lipid Search (] to determine the compositions of the fatty acid.
  20. 20. Conclusion LIMs is stable under vaccum. Give high resolution. Economically , cheap.
  21. 21. Application II
  22. 22. Challenge • Presence of adduct ions [M+Na]+ , [M+K]+ from solvent. • Contamination from solvent. • Lateral diffusion(analyte delocalization) due to solvent. Two solvent free techniques, dry-coating and sublimation
  23. 23. The dry-coating technique deposits finely ground matrix onto tissue slices by the direct filtering of solid matrix particles through a 20 μm stainless steel sieve.
  24. 24. The workflow scheme Human Ratina Salamander
  25. 25. Brain
  26. 26. Kidney
  27. 27. Human Ocular Tissue” Ratina”
  28. 28. Salamander Ratina Saturated and monounsaturated fatty acids polyunsaturated fatty acids
  29. 29. Conclusion • Sublimation is easy technique. • Reduce contamination from the solvent. • Generates a very even and uniformly thin layer. • Reduction in laser spot-to-spot
  30. 30. Summary Both Techniques” Liquid ionic and sublimation are: Easy. Available. Enhance MALDI-MSI resolution. Economically, cheap.
  31. 31. Prospective view • Combination between Liquid Ionic Matrix with Sublimation technique may be will enhance the MALDI-MSI spectra.
  32. 32. Acknowledge • Assuit university, Egypt • National sun yat sen university, ROC. • Prof. Hui-Fen Wu. • Prof. jiang. • Prof. Tseng.
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