HILL LAB RESEARCH

1
HILL LAB RESEARCH Metabolomics by MALDI-IMMS
OVERVIEW
MALDI-IMS-oTOF
CONCLUSIONS
Purpose Two dimensional analysis of
intracellular metabolites in Escherichia coli (E.
coli). Method E. coli metabolites were analyzed
by MALDI-MS and MALDI-IMS-oTOF MS. Results E.
coli metabolites were resolved using MALDI IMS-MS.

• The MALDI IMS-MS spectra shows the detection of
  800 E. coli metabolic features in the mass range
  of 50-3000 amu.
• In the mass range 50-500 amu, 200 metabolic
  features were observed in the MALDI IMS-MS plot
  while only 60 were observed in the MS plot.
• The E.coli metabolic features are resolved from
  the matrix in the MALDI IMS-MS spectra, whereas,
  the E. coli metabolic features are dominated by
  the matrix in the MS plot.
• The MALDI-IMS-MS is a fast separation technique
  that is applicable for complex biological samples
  such as the E. coli metabolome.

INTRODUCTION
This project utilizes the novel approach for the
separation and detection of metabolites in a
complex biological system, such as E.coli, by
using a MALDI-IMS-oTOF MS. The MALDI-IMS-oTOF MS
has the ability to resolve the metabolite peaks
from the background along with simultaneously
separating metabolite isomers. The
MALDI-IMS-oTOF MS is a promising method for
determination of the metabolome in complex
biological systems.
RESULTS
EXPERIMENTAL METHOD

• E. coli metabolites were extracted using methanol
  and spiked with ribitol as an internal standard.
• 2,5-dihydroxybenzoicacid was the MALDI matrix.
• A Voyager DE-RP MALDI-TOF mass spectrometer
  instrument at Washington State University was
  used for the MALDI-MS experiments.
• The MALDI-IM-oTOF system and its supporting
  electronics were designed and constructed at
  Ionwerks Inc. (Houston, TX).

ACKNOWLEDGEMENTS
This work was supported in part by a grant from
the National Institute of Health-Road Map Grant
DK070274