In partnership with Bruker JPK BioAFM, a research team at the University of Freiburg have demonstrated the practicality and value in analysis of native biological tissues across widely different length scales: macro- to nano-scale using a combination of fluorescence and atomic force microscopies.
The model system for this was human articular cartilage (AC) with the aim of identifying relationships between early macroscopic markers of osteoarthritis (OA) and functional features at the nano-scale.
As has been shown with other correlative techniques which span length scales over many orders of magnitude such as fluorescence microscopy with cryo-EM the nucleus has been identified as a convenient and reliable fiduciary marker (Ellisman lab, UCSD and others). The far-red fluorescing cell-permeant DNA dye DRAQ5™ has been chosen for these studies, as it has here in this work. Its properties enable the investigation of native, unfixed tissue (live cells) while excitation and emission light transmission is less perturbed by scatter permitting examination at greater sample depths.
Fluorescence microscopy at the millimetre sample scale showed the change in cellular organization associated with early OA and, thereby in the same sample loci, use of AFM to interrogate changes at the micro- and nano-scale such as collagen fibre modification, roughness of the AC surface and even functional properties such as elastic modulus.
This work represents another example of the breadth of application of DRAQ5™ in pursuit of correlative techniques that bridge the clinical observation with the structural and molecular background.
Reference:
Tschaikowsky, Mathaeus, Tanja Neumann, Sofia Brander, Heiko Haschke, Bernd Rolauffs, Bizan N. Balzer, and Thorsten Hugel. "Hybrid fluorescence-AFM explores articular surface degeneration in early osteoarthritis across length scales." Acta Biomaterialia 126 (2021): 315-325.
Links to related blogposts on correlative microscopy techniques:
CryoChem - from fluorescence to µCT to SBEM
Simplified CLEM method - from in vivo imaging to FIB/SEM
microCT-EM - non-destructive sample mounting
No comments :
Post a Comment