PMID- 27077488
OWN - NLM
STAT- MEDLINE
DCOM- 20161213
LR  - 20181202
IS  - 1940-087X (Electronic)
IS  - 1940-087X (Linking)
IP  - 109
DP  - 2016 Mar 24
TI  - Whole-body Mass Spectrometry Imaging by Infrared Matrix-assisted Laser Desorption 
      Electrospray Ionization (IR-MALDESI).
PG  - e53942
LID - 10.3791/53942 [doi]
LID - 53942
AB  - Ambient ionization sources for mass spectrometry (MS) have been the subject of 
      much interest in the past decade. Matrix-assisted laser desorption electrospray 
      ionization (MALDESI) is an example of such methods, where features of 
      matrix-assisted laser desorption/ionization (MALDI) (e.g., pulsed nature of 
      desorption) and electrospray ionization (ESI) (e.g., soft-ionization) are 
      combined. One of the major advantages of MALDESI is its inherent versatility. In 
      MALDESI experiments, an ultraviolet (UV) or infrared (IR) laser can be used to 
      resonantly excite an endogenous or exogenous matrix. The choice of matrix is not 
      analyte dependent, and depends solely on the laser wavelength used for 
      excitation. In IR-MALDESI experiments, a thin layer of ice is deposited on the 
      sample surface as an energy-absorbing matrix. The IR-MALDESI source geometry has 
      been optimized using statistical design of experiments (DOE) for analysis of 
      liquid samples as well as biological tissue specimens. Furthermore, a robust 
      IR-MALDESI imaging source has been developed, where a tunable mid-IR laser is 
      synchronized with a computer controlled XY translational stage and a high 
      resolving power mass spectrometer. A custom graphical user interface (GUI) allows 
      user selection of the repetition rate of the laser, number of shots per voxel, 
      step-size of the sample stage, and the delay between the desorption and scan 
      events for the source. IR-MALDESI has been used in variety of applications such 
      as forensic analysis of fibers and dyes and MSI of biological tissue sections. 
      Distribution of different analytes ranging from endogenous metabolites to 
      exogenous xenobiotics within tissue sections can be measured and quantified using 
      this technique. The protocol presented in this manuscript describes major steps 
      necessary for IR-MALDESI MSI of whole-body tissue sections.
FAU - Nazari, Milad
AU  - Nazari M
AD  - W. M. Keck FTMS Laboratory for Human Health Research, Department of Chemistry, 
      North Carolina State University.
FAU - Bokhart, Mark T
AU  - Bokhart MT
AD  - W. M. Keck FTMS Laboratory for Human Health Research, Department of Chemistry, 
      North Carolina State University.
FAU - Muddiman, David C
AU  - Muddiman DC
AD  - W. M. Keck FTMS Laboratory for Human Health Research, Department of Chemistry, 
      North Carolina State University; dcmuddim@ncsu.edu.
LA  - eng
GR  - R01GM087964/GM/NIGMS NIH HHS/United States
PT  - Journal Article
PT  - Research Support, N.I.H., Extramural
PT  - Research Support, Non-U.S. Gov't
PT  - Video-Audio Media
DEP - 20160324
PL  - United States
TA  - J Vis Exp
JT  - Journal of visualized experiments : JoVE
JID - 101313252
SB  - IM
MH  - Histocytological Preparation Techniques/*methods
MH  - Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization/*methods
PMC - PMC4841315
EDAT- 2016/04/15 06:00
MHDA- 2016/12/15 06:00
PMCR- 2018/03/24
CRDT- 2016/04/15 06:00
PHST- 2016/04/15 06:00 [entrez]
PHST- 2016/04/15 06:00 [pubmed]
PHST- 2016/12/15 06:00 [medline]
PHST- 2018/03/24 00:00 [pmc-release]
AID - 53942 [pii]
AID - 10.3791/53942 [doi]
PST - epublish
SO  - J Vis Exp. 2016 Mar 24;(109):e53942. doi: 10.3791/53942.