FIG. 1.

Direct binding (counts per minute) of human fibrinogen (A) and fibronectin (B) by GAS isolate CS101 and Tn917 mutant CS101:ZQ6. After growth in THB at 37°C overnight, bacteria were harvested and washed with 0.15 M Veronal buffered saline, pH 7.35, containing 0.1% gelatin. Different numbers of cells were then incubated with ¹²⁵I-human fibrinogen or ¹²⁵I-human fibronectin, as described in Materials and Methods. Following three washings binding was measured in a gamma counter. All estimations were carried out in duplicate, and <5% variation was observed between samples.