Expression of CD55 and CD59 antigens on CD34⁺ cells derived from normal BM. CD34⁺ cells were separated using an affinity column and stained with Cy-PE conjugated anti-CD34 MoAb (A) and with PE-conjugated anti-CD59 and FITC-conjugated anti-CD55 MoAb (A). Cells were gated as indicated in (A) and then analyzed as shown in (B). When CD34-purified cells were stained with PE-conjugated anti-CD59 and FITC-conjugated anti-CD34 MoAbs. (C) CD59 expression on CD34⁺ cells before PPLC digestion. Specificity of CD59 staining for GPI-anchored form was confirmed by PPLC-digestion. After 20 minutes of PPLC treatment, PE-fluorescence, indicating expression of CD59, was measured (D). (A) Log Cy-PE fluorescence intensity versus cell number; (B) and (C) log PE fluorescence intensity versus log FITC fluorescence intensity; (D) log PE fluorescence intensity versus cell number.