FIG. 4.
CHO cell-binding assay. Microtiter plates were coated with 2 μg of each purified protein, and 100 μl of a 3 × 105 cells/ml suspension of CHO cells transfected with DAF (CHO DAF+) or control CHO cells without DAF (CHO DAF−) was added to each well. Bound cells were lysed and quantified by detection of released LDH. MBP-DraE cleaved, MBP-DraE cleaved with Factor Xa. Each protein sample was examined in triplicate in at least three independent experiments. Representative averages from triplicate wells with the standard deviations are shown.