Differential effects of HDAC inhibitors on the repressing potential of HIC-1, γFBP-B, and BCL-6. RK13 cells were transiently transfected in triplicate with 200 ng of the indicated GAL4-chimeras and 750 ng of the pG5LUC reporter. Twenty-four hours later, the cells were treated with 300nM TSA (from a ×1,000 concentrated DMSO dissolved stock) (black box) or 5 mM NaBu (grey box) or mock treated with an equal volume of DMSO (vehicle, open box) for a further 24 hr before harvesting. The luciferase activity was normalized to the β-gal activity of a cotransfected pSG5 β-gal construct (50 ng).