Relative Quantification of Cellular Sections with Molecular Depth Profiling ToF-SIMS Imaging

Area of Science:

• Cell biology
• Biophysics
• Analytical chemistry

Background:

• Lipid distribution within single cells is crucial for cellular function.
• Quantifying lipid differences between cellular compartments (plasma membrane and cytoplasm) presents analytical challenges.
• Existing methods may lack the spatial resolution or sensitivity for detailed lipid profiling.

Purpose of the Study:

• To develop and demonstrate a SIMS imaging approach for quantifying relative lipid differences between the plasma membrane and cytoplasm of single cells.
• To utilize lipophilic dyes as markers for cell identification and depth profiling within SIMS analysis.
• To establish a method for comparing lipid headgroup amounts in treated versus control cells.

Main Methods:

• Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) imaging with a C(60)(+) ion source.
• Labeling of cells with lipophilic dyes for membrane identification and depth analysis.
• Cryo-fracturing of cells to expose internal structures (plasma membrane and cytoplasm).
• Analysis of multiple cellular sections following a single fracture event.

Main Results:

• Successful quantification of relative lipid amounts between the plasma membrane and cytoplasm in single cells.
• Demonstration of lipophilic dyes as effective markers for cell population identification and membrane depth profiling.
• Validation of the ability to compare specific lipid headgroup quantities in treated cells versus control cells.
• Showcased the capacity to analyze multiple cellular sections from a single fracture.

Conclusions:

• SIMS imaging provides a powerful tool for quantitative lipid analysis within distinct cellular compartments.
• The developed method allows for comparative lipid profiling between different cell populations or treatment conditions.
• This approach offers a foundation for detailed investigations into cellular lipidomics and membrane biophysics.