Fig. 6. Binding of ¹²⁵I-FN to FN^-/- cell layers. Confluent FN^-/- cell layers grown in 48 well plates were incubated for 1 hour at 37°C with 0.2 ml defined medium containing 0.2% BSA and increasing concentrations of ¹²⁵I-FN. Nonspecific binding (closed triangles) was determined by adding excess unlabeled FN (500 µg/ml) to the incubation medium. Specific binding (closed circles) was assessed by subtracting nonspecific binding from total binding (open squares). Each point represents the average of triplicate determinations from a representative experiment. Bars represent±s.e.m.