Colorimetric Determination of Diazo-dyes Affinity for Elastic Tissue and Model Proteins

A model system was established which could serve for the quick and reliable estimation of the possibility to use aromatic dyes in staining elastic fibers and lamellas. Specially prepared samples of aorta wall tissue (taken from the corpse material of a healthy male, aged 31) and model proteins (collagen and elastin) were stained with acid diazo-dyes applied in water solution, 70% ethanol and dimethyl-sulfoxide. The amount of bonded dye was determined quantitatively according to the difference in absorbance of dye solution before and after the sample staining. The results of colorimetric measurements clearly showed a good correlation between the chemical structure of dyes and their binding to substrate, thus indicating the possibility that this model system cuold be used for simple and quick choice of dye solvent as well as particular aromatic dyes which should be used for elastic fibers dyeing in light microscopy.