Detection of CXCR-4 (A) and CKR-5 (B) mRNA in samples of CD34⁺ cells of 9 leukapheresis products using RT-PCR. Chemokine mRNA specific PCR, Southern Blot hybridization, and GAPDH-PCR are shown one below another. For CXCR-4 mRNA, the cell line HL60 served as a positive control and SK-N-MC and water as negative controls. CKR-5 mRNA analysis of cell line KG-1a was a positive control, whereas HL60 and water were negative controls.