title: Are the polarization colors of picrosirius red-stained collagen determined only by the diameter of the fibers?
abstract: Polarization colors of various purified collagens were studied in fibers of similar thickness. Three different soluble collagens of type I, insoluble collagen type I, lathyritic collagen type I, two p-N-collagens type I, pepsin extract collagen type II, two soluble collagens type III, p-N-collagen type III, and soluble collagen type V were submitted to a routine histopathologic procedure of fixation, preparation of 5-microns-thick sections, staining with Picrosirius red and examination under crossed polars. Polarization colors were determined for thin fibers (0.8 micron or less) an thick fibers, (1.6-2.4 microns). Most thin fibers of collagens and p-N-collagens showed green to yellowish-green polarization colors with no marked differences between the various samples. Thick fibers of all p-N-collagens, lathyritic and normal 0.15 M NaCl-soluble collagens showed green to greenish-yellow polarization colors, while in all other collagens, polarization colors of longer wavelengths (from yellowish-orange to red) were observed. These data suggested that fiber thickness was not the only factor involved in determining the polarization colors of Picrosirius red-stained collagens. Tightly packed and presumably, better aligned collagen molecules showed polarization colors of longer wavelengths. Thus, packing of collagen molecules and not only fiber thickness plays a role in the pattern of polarization colors of Picrosirius red-stained collagens.
authors: Section of Oral Pathology and Oral Medicine, Maurice and Gabriela Goldschleger School of Dental Medicine, Tel Aviv University, Israel.
authors: D
authors: D
authors: Dayan
authors: Y
authors: Y
authors: Hiss
authors: A
authors: A
authors: Hirshberg
authors: J J
authors: JJ
authors: Bubis
authors: M
authors: M
authors: Wolman
mesh_terms: D000818:Animals; D001391:Azo Compounds; D002417:Cattle; D003094:Collagen / Q000032:analysis* / Q000145:classification; D003116:Color; D004396:Coloring Agents; D006801:Humans; D008859:Microscopy, Polarization; D010851:Picrates; D051381:Rats; D013194:Staining and Labeling
chemical_list: D001391:Azo Compounds; D004396:Coloring Agents; D010851:Picrates; C009798:C.I. direct red 80; D003094:Collagen