Validity of high-resolution flow cytometry. (A) An example of analysis on a patient with PNH⁺ AA is shown. Gates were set up to exclude SSC^dim (i) and CD11b^dim granulocytes and glycophorin A^dim RBCs (ii,v). Cells within rectangles showing horizontal distribution represent PNH-type cells. (B) RBCs from a healthy individual and a patient with AA were examined using a low-resolution assay and the high-resolution assay. Numbers on histograms denote the percentages of CD55^-CD59^- cells in total RBCs for the low-resolution assay, and in glycophorin A⁺ RBCs for the high-resolution assay. (C) RBCs from a patient with PNH⁺ AA were incubated in acidified saline containing heat-inactivated or untreated serum. CD55^-CD59^- RBCs were then quantified. (D) PNH⁺ AA WBCs were incubated with or without 0.5 × 10^-8 M aerolysin and analyzed by flow cytometry.