1 research outputs found
Single Cell Analysis with Probe ESI-Mass Spectrometry: Detection of Metabolites at Cellular and Subcellular Levels
Molecular analysis at cellular and
subcellular levels, whether
on selected molecules or at the metabolomics scale, is still a challenge
now. Here we propose a method based on probe ESI mass spectrometry
(PESI-MS) for single cell analysis. Detection of metabolites at cellular
and subcellular levels was successfully achieved. In our work, tungsten
probes with a tip diameter of about 1 Ī¼m were directly inserted
into live cells to enrich metabolites. Then the enriched metabolites
were directly desorbed/ionized from the tip of the probe for mass
spectrometry (MS) detection. The direct desorption/ionization of the
enriched metabolites from the tip of the probe greatly improved the
sensitivity by a factor of about 30 fold compared to those methods
that eluted the enriched analytes into a liquid phase for subsequent
MS detection. We applied the PESI-MS to the detection of metabolites
in single Allium cepa cells. Different
kinds of metabolites, including 6 fructans, 4 lipids, and 8 flavone
derivatives in single cells, have been successfully detected. Significant
metabolite diversity was observed among different cells types of A. cepa bulb and different subcellular compartments
of the same cell. We found that the inner epidermal cells had about
20 fold more fructans than the outer epidermal cells, while the outer
epidermal cells had more lipids. We expected that PESI-MS might be
a candidate in the future studies of single cell āomicsā