Single-Cell Metabolomics with Rapid Determination of Chemical Formulas from Isotopic Fine Structures

Area of Science:

• Cellular and Molecular Biology
• Analytical Chemistry
• Biophysics

Background:

• Metabolomics offers functional insights into cellular states and phenotypes.
• Existing single-cell metabolomics methods often require extensive sample processing.
• There is a need for direct, high-confidence metabolite identification at the single-cell level.

Purpose of the Study:

• To present a protocol for direct, untargeted single-cell metabolomics.
• To enable high-confidence identification of metabolite molecular formulas from single cells.
• To complement existing single-cell omics techniques.

Main Methods:

• Combining fiber-based laser ablation electrospray ionization (f-LAESI) with a 21 Tesla Fourier transform ion cyclotron resonance mass spectrometer (21T-FTICR-MS).
• Utilizing mid-infrared laser ablation for direct ambient analysis of cells without sample processing.
• Measuring isotopic fine structure (IFS) for rapid computational determination of elemental compositions.

Main Results:

• Direct, untargeted detection of a broad range of metabolites from single cells.
• High confidence in the discovery and identification of molecular formulas for detected metabolites.
• Simultaneous measurement of IFS for numerous metabolites, enabling accurate elemental composition determination.

Conclusions:

• The developed f-LAESI and 21T-FTICR-MS protocol provides a powerful tool for single-cell metabolomics.
• This technique allows for direct ambient analysis, reducing sample preparation artifacts.
• It complements transcriptomics and proteomics by revealing intracellular molecular interactions previously inaccessible.