Subcellular localisation and identification of single atoms using quantitative scanning transmission electron...

Area of Science:

• * Biophysics
• * Cell Biology
• * Materials Science

Background:

• * Elemental distribution within subcellular structures is crucial for cell function but challenging to measure.
• * Existing techniques lack the spatial resolution and sensitivity for subcellular elemental quantification.
• * Platinum-based chemotherapeutics like oxaliplatin are vital for cancer treatment but can cause side effects.

Purpose of the Study:

• * To establish a novel methodology for high-resolution elemental localization and quantification within biological samples.
• * To demonstrate the capability of scanning transmission electron microscopy (STEM) for detecting and measuring elements at the subcellular level.
• * To validate the methodology using platinum (Pt) deposition in neuronal cells treated with oxaliplatin.

Main Methods:

• * Utilized scanning transmission electron microscopy (STEM) with annular dark-field (ADF) imaging.
• * Measured elastic electron scattering to identify and quantify high-Z elements.
• * Applied the technique to detect platinum (Pt) atoms and clusters in neuronal cell bodies post-oxaliplatin administration.

Main Results:

• * Achieved single-atom and nanoscale cluster visualization of platinum (Pt) within subcellular structures.
• * Quantified absolute Pt atom numbers per cluster using elastic electron scattering intensity.
• * Determined cluster densities below that of metallic platinum and demonstrated potential for detecting elements as light as sodium.

Conclusions:

• * The developed STEM-based methodology enables unprecedented subcellular elemental localization and quantification.
• * This technique provides new insights into cellular elemental distributions and their functional implications.
• * The method holds promise for detecting a wide range of elements, including light elements like sodium, in biological systems.