Correlated optical and isotopic nanoscopy

Area of Science:

• Cell Biology
• Microscopy
• Biophysics

Background:

• Secondary ion mass spectrometry (SIMS) images isotopic composition in biological samples, primarily for studying cellular metabolism and turnover using stable isotopes (e.g., 15N, 13C).
• SIMS offers high resolution (sub-100 nm) but cannot identify specific subcellular structures like organelles, necessitating correlation with other imaging techniques such as fluorescence microscopy.
• Understanding organelle-specific protein turnover is crucial for comprehending cellular dynamics and function.

Purpose of the Study:

• To develop a novel imaging method that correlates optical and isotopic information at the nanoscale.
• To investigate protein turnover dynamics within specific organelles of cultured hippocampal neurons.

Main Methods:

• Development of Correlated Optical and Isotopic Nanoscopy (COIN) based on stimulated depletion microscopy.
• Application of COIN to analyze the incorporation and distribution of stable isotope-labeled amino acids in cultured neurons.
• Correlation of high-resolution optical images with isotopic composition data at the subcellular level.

Main Results:

• COIN successfully generated images combining optical and isotopic data with nanoscale resolution.
• The method enabled the study of protein turnover within distinct organelles of hippocampal neurons.
• Demonstrated the capability to visualize isotopic composition within specific subcellular compartments.

Conclusions:

• COIN is a powerful new technique for high-resolution imaging of isotopic composition in biological samples.
• This method overcomes the limitations of traditional SIMS by enabling subcellular structure identification.
• COIN has broad applicability for investigating organelle-specific molecular dynamics and isotopic composition across various biological systems.