JPK Instruments has supplied a Nanowizard AFM system that has been used to reveal the nanostructure and mechanics of mummified type I collagen.
In the Department of Earth and Environmental Sciences at the Ludwig-Maximilians University in Munich, scientists work on nanoscale biomaterial characterisation.
Their efforts have recently been showcased in the study of mummified skin from the 5,300-year-old Tyrolean Iceman.
To determine the degree of tissue preservation in mummified human skin and the reason for its durability, PhD student Marek Janko of Prof Robert Stark's research group has investigated the structural integrity of its main protein, type I collagen, using an atomic force microscope, the Nanowizard II, from JPK Instruments.
Janko's research focuses on the study of mechanical properties of nanobio materials.
Use of AFM and Raman spectroscopy are non-invasive techniques and samples may be re-analysed many times.
The choice of the Nanowizard for this work is twofold.
The combination of AFM with optical microscopy enables normal histology tissue samples, two to four microns thick and relatively 'rough', to be readily studied in ambient conditions.
The optical microscope enables identification of areas for study and then the AFM is used to effectively zoom in to study individual fibrils on the tens of nanometre scale.
Being able to zoom in and study a single fibril just 30-40nm in height means the individual repeat units of 67nm may be identified and probed.
This enables nano-indentation studies to be carried out employing force-versus-distance measurements to measure mechanical properties and, in particular, Young's modulus.
