Fig. 1.

Collagen content assay using Picro-Sirius red staining. A: The amount of collagen in cultured human fibroblasts exposed to sera from four sources: SSc subjects, healthy individuals, FBS, and FBS supplemented TGF-β1 (10 ng/mL). Each condition was tested in triplicate. Collagen content was significantly different among the four groups (P =0.0001), as determined by the nonparametric Kruskal-Wallis with Dunn-Bonferroni post hoc testing. Each bar demonstrates means ± SEM for normally distributed values. The dots in the graph show value for each replicate. *P < 0.05, *** P < 0.001, **** P < 0.0001. B: The microscopic appearance of human dermal fibroblasts stained with Picro-Sirius red to demonstrate collagen accumulation