High-spatial-resolution maps of sulphur from human hair sections: an EELS study

Area of Science:

• Materials Science
• Microscopy
• Biophysics

Background:

• Accurate mapping of sulphur distribution in biological samples like human hair is crucial for understanding its structure and properties.
• Previous methods for visualizing sulphur at the electron microscopic level, such as silver staining, had limitations.

Purpose of the Study:

• To develop and validate a high-resolution method for mapping sulphur distribution in human hair using electron energy-loss spectroscopy (EELS).
• To compare the effectiveness of different embedding resins for EELS analysis of hair samples.

Main Methods:

• Human hair shafts were embedded in three different resins: Nanoplast, Spurr, and Lowicryl.
• Ultrathin sections were analyzed using a Zeiss CEM 902A transmission electron microscope with an energy filter.
• Electron energy-loss spectroscopy (EELS) was employed to detect and map sulphur.

Main Results:

• High-resolution sulphur maps of human hair were successfully generated using EELS.
• Nanoplast resin provided the best image contrast among the tested resins.
• The EELS results confirmed the findings of previous sulphur detection methods using silver staining.

Conclusions:

• EELS is a powerful technique for high-resolution sulphur mapping in human hair.
• The study validates EELS as a reliable alternative to traditional silver staining for sulphur visualization in electron microscopy.
• This method allows for more detailed analysis of local sulphur concentrations in hair structures.