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

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. Outline
Introduction
-MALDI-TOF.
-Lipids.
Application I.
Application II.
Summary.
Discussion and Questions.

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. 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. Matrix Assisted Laser Desorption
Ionization MALDI
Beate Fuchs et.al. Progress in Lipid Research 2010.49 ,450–475

6. Alexandra P. Kafkaa et.al. International Journal of Pharmaceutics 2011,417 70– 82
Matrix

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. 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. 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. http://www.nationwidechildrens.org/gaucher-disease
http://www.childclinic.net/metabolic/Fabry_disease.html
http://www.sehha.com/diseases/neuro/Alzheimer.htm
Wolman Disease, and
Lysosomal acid lipase LAL deficiency .Cell death

11. Application I

12. The workflow scheme
CH3
OH
OH
O
OH
OH
OH
O

13. Cryostat (Leica)

14. CH3
OH
OH
O
OH
OH
OH
O

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. (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).

19. (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

20. MALDI(+)

23. Lipid Search (http://www.lipidmaps.org/)] to determine the compositions of the fatty
acid.

28. Conclusion
LIMs is stable under vaccum.
Give high resolution.
Economically , cheap.

29. Application II

30. 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

31. 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.

32. The workflow scheme
Human
Ratina
Salamander

33. Brain

34. Kidney

35. Human Ocular Tissue” Ratina”

36. Salamander Ratina
Saturated and
monounsaturated
fatty acids
polyunsaturated fatty acids

37. Conclusion
• Sublimation is easy technique.
• Reduce contamination from the solvent.
• Generates a very even and uniformly thin layer.
• Reduction in laser spot-to-spot

38. Summary
Both Techniques” Liquid ionic and sublimation are:
Easy.
Available.
Enhance MALDI-MSI resolution.
Economically, cheap.

39. Prospective view
• Combination between Liquid Ionic Matrix with
Sublimation technique may be will enhance
the MALDI-MSI spectra.

40. Acknowledge
• Assuit university, Egypt
• National sun yat sen university, ROC.
• Prof. Hui-Fen Wu.
• Prof. jiang.
• Prof. Tseng.