Abstract
Rationale Laser microdissection coupled directly with mass spectrometry provides the capability of on-line analysis of substrates with high spatial resolution, high collection efficiency, and freedom on shape and size of the sampling area. Establishing the merits and capabilities of the different sampling modes that the system provides is necessary in order to select the best sampling mode for characterizing analytically challenging samples. Methods The capabilities of laser ablation spot sampling, laser ablation raster sampling, and laser 'cut and drop' sampling modes of a hybrid optical microscopy/laser ablation liquid vortex capture electrospray ionization mass spectrometry system were compared for the analysis of single cells and tissue. Results Single Chlamydomonas reinhardtii cells were monitored for their monogalactosyldiacylglycerol (MGDG) and diacylglyceryltrimethylhomo-Ser (DGTS) lipid content using the laser spot sampling mode, which was capable of ablating individual cells (~4-15 μm) even when agglomerated together. Turbid Allium Cepa cells (~150 μm) having unique shapes difficult to precisely measure using the other sampling modes could be ablated in their entirety using laser raster sampling. Intact microdissections of specific regions of a cocaine-dosed mouse brain tissue were compared using laser 'cut and drop' sampling. Since in laser 'cut and drop' sampling whole and otherwise unmodified sections are captured into the probe, 100% collection efficiencies were achieved. Laser ablation spot sampling has the highest spatial resolution of any sampling mode, while laser ablation raster sampling has the highest sampling area adaptability of the sampling modes. Conclusions Laser ablation spot sampling has the highest spatial resolution of any sampling mode, useful in this case for the analysis of single cells. Laser ablation raster sampling was best for sampling regions with unique shapes that are difficult to measure using other sampling modes. Laser 'cut and drop' sampling can be used for cases where the highest sensitivity is needed, for example, monitoring drugs present in trace amounts in tissue. Published in 2016. This article is a U.S. Government work and is in the public domain in the USA.
| Original language | English |
|---|---|
| Pages (from-to) | 611-619 |
| Number of pages | 9 |
| Journal | Rapid Communications in Mass Spectrometry |
| Volume | 30 |
| Issue number | 5 |
| DOIs | |
| State | Published - Mar 15 2016 |
Funding
Amina S. Woods, Shelley Jackson, and Aurelie Roux (National Institute of Drug Abuse-Intramural Research Program,National Institutes of Health) are thanked for supplying the mouse brain tissue. The TripleTOF 5600 mass spectrometer used in this work was provided on loan and the brain tissue studies funded by SCIEX through a Cooperative Research and Development Agreement (CRADA NFE-10-02966). Julian Burke (Leica Microsystems) is thanked for the loan of the LMD7000 instrument. The fundamental instrumental advancement and algae and plant studies were supported by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, Chemical Sciences, Geosciences, and Biosciences Division. This manuscript has been authored by UT-Battelle, LLC, under Contract No. DE-AC05-00OR22725 with the U.S. Department of Energy. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that theUnited StatesGovernment retains a non-exclusive, paidup, irrevocable, world-wide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes. The Department of Energy will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan (http://energy.gov/downloads/doe-public-access-plan).