The enhancing mAb traps MR1 at the cell surface. CH27. mMR1 were incubated with medium alone, mouse IgG1 isotype control, 8F2.F9, or 8H9.D11 for 2 h or overnight before staining with 8F2.F9-AF647 and analysis by flow cytometry. A, Staining of CH27.mMR1 from the different overnight incubations from one of three experiments. B, 8F2. F9-AF647 staining of CH27.mMR1 from the 2-h or overnight incubations is shown as the percentage of the staining of the medium control in A. The plot shows the mean percentage (± SD) from three independent experiments.