Fig. 1. PGI/AMF binding to cell surface fibrils requires FN expression. FN^+/– (A-C,G-I) and FN^–/– (D-F,J-L) fibroblasts were plated for 2 days on glass cover slips. The cells were incubated with 25 µg ml^–1 PGI/AMF conjugated to Alexa-568 (PGI/AMF-568) for 30 minutes at 37°C in medium buffered to pH 7.5 with Hepes (A-F) or to pH 5.0 with MES (G-L) and then fixed with 3% paraformaldehyde. PGI/AMF-568 labeling is shown in red (A,D,G,J) and FN labeled with mouse anti-FN mAb and Alexa-488 conjugated anti-mouse secondary antibody shown in green (B,E,H,K). Merged images show co-localization of the two in yellow (C,F,I,L). Bar, 10 µm.