FIG. 3.

Binding of viruses to CHO cells without (solid bars) or with (hatched bars) previous digestion with heparinase I. The cells were either digested with 8 U of heparinase I (in phosphate-buffered saline with 0.1% BSA/ml) or mock-digested (phosphate-buffered saline with 0.1% BSA only) for 1 h at 37°C followed by processing for attachment assays as described in Materials and Methods. The bars represent averages of triplicate binding assays with 10⁵ cpm of virus and ∼10⁶ cells per reaction. Each set of triplicates was repeated at least twice. The error bars represent standard deviations.