Northern blot analysis probed with a 760-bp fragment of the IL-10 cDNA demonstrating IL-10 transcript content of PBMNCs from adult (upper panel), term (middle panel), and preterm blood (lower panel) in the absence of LPS (C, lane 1) and cultured for 10 hours with LPS (1 μg/mL), then treated with actinomycin D (10 μg/mL) at time 0, 15, 30, 60, and 90 minutes (lanes 2-6, respectively). RNA loading is standardized using 18S ribosomal RNA bands.