Fig. 1.

Differentiation of ASCs. (a, b) Adipogenic differentiation of ASCs, Oil Red stain, (15 days of cultivation; objective lens 20×, eyepiece 10×; phase contrast). (a) control — culture of third passage ASCs without using a differentiating medium, the subconfluent monolayer is formed by typical fibroblast-like cells. In the cells of the control culture, the formation of fat vacuoles is not fixed. (b) the culture of ASCs after cultivation in a differentiating medium. Fat culture vacuoles are clearly defined in culture cells stained with a specific Red Oil dye. The presence of fat vacuoles in the cells indicates the ability of ASC to differentiate in the adipogenic direction; (c, d) Osteogenic differentiation of ASCs. Osteogenic differentiation of ASCs, stained with alizarin red (15 days of cultivation; objective lens 10×, eyepiece 10×, light microscopy). (c) The control culture of ASCs is presented as a subconfluent monolayer formed by morphologically identical spindle-shaped cells, with no calcium deposits. (d) The culture of ASCs after cultivation in a special differentiating medium. The culture is a subconfluent monolayer. Calcium deposits are clearly visualized, which are stained with a differentiating dye, alizarin red. Calcium deposits indicate the ability of ASC to differentiate in the osteogenic direction; (f) Chondrogenic differentiation of ASCs. Staining of type II collagen deposits in the pellet with polyclonal antibodies (Abcam, ab34712; cell nuclei stained with hematoxylin and eosin (Sigma-Aldrich, Germany); objective lens 20×, eyepiece 10×). Ball formation and deposition of type II collagen in them indicates chondrogenic differentiation of ASCs.