103B2/9E10 and 105.A5 MoAbs recognize the same glycoprotein antigen on transfectants expressing the CD164 cDNA. A 2.7-kb BamHI-Xho I restriction fragment of the CD164 cDNA (harboring both the entire coding sequence and the 5′ and 3′ noncoding regions) was subcloned into the pRUFneovector and subsequently introduced into FDC-P1 cells by retroviral transduction (refer to Materials and Methods). The resultant G418-resistant cell population was stained by indirect immunofluorescence and analyzed by flow cytometry. Data are displayed as single-parameter fluorescence (FITC) histograms of 1 × 10⁴ light-scatter gated events, collected as list mode data. (···) IgG₃ control MoAb; (-·-) IgM control MoAb; (—) MoAb 103B2/9E10; () MoAb 105.A5