Poster Presentation HUPO 2019 - 18th Human Proteome Organization World Congress

Characteristics of MALDI-imaging on a new dual ion source QTOF with TIMS separation (#917)

Arne Fuetterer 1 , Juergen Suetering 1 , Janina Oetjen 1 , Nils Goedecke 1 , Stephanie Kaspar-Shoenenfeld 1 , Scarlet Koch 1 , Pierre-Olivier Schmit 2 , Shannon Cornett 3 , Alice Ly 1 , Lucy Woods 1 , jens Fuchser 1 , Oliver Raether 1 , jens Hoendorf 1
  1. Bruker Daltonik GmbH, Bremen, Germany
  2. Bruker France, Wissembourg, France
  3. Bruker Daltonics Inc, Billerica, MA, USA

Background

MALDI Imaging has a broad range of applications in Omics research. However, a gap exists between desired mass resolution capabilities and the acquisition speed of current instrumentation. We present initial results from the timsTOF flex system; a timsTOF Pro QTOF mounted with a high-throughput, high spatial resolution MALDI source and stage.

Methods

A timsTOF Pro was mounted with a MALDI source and 10 kHz smartBeam 3D laser featuring electronically controlled spot positioning and beam profile for imaging. Performance in ESI mode was evaluated by analyzing a commercially available HeLa digest (Pierce) using DDA PASEF approach. Tissue samples for MALDI-MSI were mounted on conductive glass slides, and coated with matrix using standard protocols on a TM Sprayer (HTX Technologies, Chapel Hill, NC, USA). MALDI ion mobility imaging experiments were acquired on the system at a mobility resolution of 150 1/K0.

Findings

High spectral quality MALDI Imaging data could be acquired at a rate of up to 20 pixels/second in both positive and negative mode. A sagittal rat brain section consisting of approximately 370,000 pixels took ~5 hours to measure. Spatial resolution of 20 ┬Ám was confirmed by matching ion signals to specific cells and structures in rat brain. In experiments designed to stress the system, 20 hours of image acquisition or ~1.5 million pixels showed no decline in imaging dataset quality and a mass deviation of RMS 2.06 without lock mass. Trapped ion mobility imaging measurements removed isobaric interferences in lipid imaging.

Proteomics analysis s was used to assess if the dual source design and MALDI Imaging experiments affected LC-MS/MS performance. Injections of 200ng HeLa revealed over 5000 protein groups identified; this figure is maintained over the course of measuring 20 million MALDI pixels.

Conclusion:

The timsTOF fleX allows for fast, high-spatial resolution MALDI acquisition, and robust ESI performance.