FIG. 2.

Expression of the chemokine receptors CCR1, CCR2b, CCR3, CCR5, and CXCR4 in maturing monocytes. Total RNAs from nonadherent cells (day 0; lanes 0) and adherent cells at days 1, 3, and 7 (lanes 1, 3, and 7, respectively) were extracted, treated with RNase-free DNase (Boehringer), and used in RT-PCR. Products were amplified with primer pairs specific for each chemokine receptor or for GAPDH (see the text). Amplified DNA fragments were visualized on ethidium bromide-stained agarose gels under UV transillumination and photographed. To exclude DNA contamination, mock PCRs were run in parallel without reverse transcriptase (lanes C1) or without the cDNA template (lanes C2).