Cytometric bead array on aged and young BM andreal-time PCR analysis for Rantes expression in old and young BM populations. Cytokine levels in the BM were detected with a mouse cytokine bead array and FacsArray plate reader (both from BD Biosciences). We purchased each cytokine's cytometric bead array kit from BD Biosciences which can detect picogram levels of protein in serum or cell-culture supernatant (Flex set; BD Biosciences) and used in a multiplex manner. (A) Graph represents protein levels of cytokines either in the old or young BM supernatant normalized to total protein levels. (B) Graph represents Mig and Rantes protein levels either in the old or young BM supernatant (n = 10 young, n = 6 old). (C) Quantitave real-time PCR analysis of Rantes on mRNA purified from old or young bone cells, lineage-positive and hematopoietic stem-progenitor (KLS) cells (n = 3 young, n = 3 old). Error bars represent SEM.