Fig. 3. CoCl₂ decreased MSC proliferation. (A,B) BrdU incorporation of MSCs cultured with or without 100 µM CoCl₂. BrdU was incorporated only for the last 2 hours of treatment. (A) BrdU immunostaining using DAB-nickel after 24 hours of treatment. (B) Percentage of BrdU-positive MSCs cultured with or without 100 µM CoCl₂ after 6, 24 and 48 hours of treatment. Data shown are mean ± s.e.m. from three independent MSC preparations and from three different wells in each experiment. *P<0.05, Student's t-test, CoCl₂-treated cells were compared with control cells. (C) Expression of cell-cycle-related genes was analysed by real-time RT-PCR after 6 and 24 hours of CoCl₂ treatment, n=3, *P<0.05, univariate Student's t-test.