Fig 3. FACS histograms of ²¹¹At-BC8-B10, BC8-B10 and BHV1 (isotype matched control) binding to Ramos cells.

Duplicate samples of ²¹¹At-BC8-B10 were obtained from three production runs used to qualify the radiolabeling process. The ratio of mean fluorescence intensity (MFI) values for the ²¹¹At-BC8-B10 to BC8-B10 provides information on how the antibody binding has been affected by the radiolabeling process. A value of >50% MFI by flow cytometry for CD45 positive cell binding of the ²¹¹At-BC8-B10 relative to non-labeled BC8-B10 is used as the cutoff for release using this assay. This value has been used previously in clinical trials with ¹³¹I-labeled BC8.