Immunofluorescent staining of Pg incorporated into the matrix produced by fibroblasts. WI38 fibroblasts were cultured in DMEM for 72 hours to produce ECM. Cells in selected wells were cultured with soluble plasma fibrinogen for an additional 2 hours, and the fibrin film formed on the surface of the cell layer was removed. Glu-Pg was added for 1 hour to wells with and without added fibrinogen. Cells were fixed and then incubated with mAb 8A11 against fibronectin (5 μg/mL), mAb 4-2 against fibrinogen (5 μg/mL), and polyclonal Ab against Pg (1:1000). Double immunostaining with anti-Fn (A) and anti-Pg (D). (B,E) Staining with anti-Fn and anti-Pg, respectively. (C,F) Staining with anti-Fg and anti-Pg, respectively.