Advanced Microscopy

Digital Densitometry 

MIPT facilities include Carl Zeiss Axio Scope A1 microscope with a QImaging QICAM camera used for digital densitometry (DD) analysis. The system utilizes bandpass filters to quantitatively measure certain wavelength monochromatic light present in histological staining protocols. Our DD system is equipped with 3 different bandpass filters are utilized for quantitative analysis of different staining protocols: 

- Masson’s trichrome: 625 nm 
- Picrosirius red: 550 nm 
- Safranin-O: 492 nm  

Polarized Light Microscopy 

Our facilities have Nikon Diaphot TMD microscope equipped with Abrio PLM imaging system. The Abrio system consists of a green bandpass filter, a circular polarizer, and a computer-controlled analyzer composed of two liquid crystal polarizers, and a CCD camera. The system can be used for automated measurement of the magnitude of retardance in birefringent materials such as tissue sections. 

 

Figure 1. Safranin O, cluster and PLM images from three samples with different severity of OA. The corresponding cluster images from the carbohydrate region are extracted from the combined hyperspectral data.  

Figure adapted from:  Oinas, J., Rieppo, L., Finnilä, M. et al. Imaging of Osteoarthritic Human Articular Cartilage using Fourier Transform Infrared Microspectroscopy Combined with Multivariate and Univariate Analysis. Sci Rep 6, 30008 (2016). https://doi.org/10.1038/srep30008  

Figure 2. Correlations between the DD or PLM and FTIR-derived collagen contents at different layers of cartilage.  

Figure adapted from: Rieppo L, Janssen L, Rahunen K, Lehenkari P, Finnilä MAJ, Saarakkala S. Histochemical quantification of collagen content in articular cartilage. PLoS One. 2019;14(11):e0224839. Published 2019 Nov 7. doi:10.1371/journal.pone.022483

 

Last updated: 26.5.2020