Profiling and quantifying endogenous molecules in single cells using nano-DESI MS

Area of Science:

• Analytical Chemistry
• Cell Biology
• Biochemistry

Background:

• Single-cell molecular profiling is crucial for understanding cellular functions in health and disease.
• Rapidly turning-over small molecules reveal metabolic pathways and cellular events like differentiation.
• Current techniques lack the throughput for comprehensive single-cell metabolic variability analysis.

Purpose of the Study:

• To demonstrate the capability of nanospray desorption electrospray ionization mass spectrometry (nano-DESI MS) for high-throughput single-cell molecular profiling.
• To enable sensitive detection and quantification of endogenous metabolites in individual cells.
• To establish a foundation for future studies on cellular processes.

Main Methods:

• Utilized nanospray desorption electrospray ionization mass spectrometry (nano-DESI MS) for single-cell analysis.
• Developed a method for sensitive detection of endogenous amino acids and phospholipids.
• Incorporated a phosphatidylcholine internal standard for absolute quantification.

Main Results:

• Successfully detected a wide range of amino acids and phospholipids, including plasmalogens, from single human cheek cells.
• Quantified the total amount of phosphatidylcholine (PC) in a single cell to be 1.2 pmoles.
• Demonstrated an automated, higher-throughput approach for single-cell molecular profiling.

Conclusions:

• nano-DESI MS is a powerful tool for sensitive, high-throughput molecular profiling of single cells.
• This technique facilitates the study of cellular heterogeneity and metabolic pathways.
• The developed methods support future research into drug effects, cell differentiation, and microenvironment influences.