Analysis of histone post-translational modifications (PTMs) in response to γ-irradiation, α-particles, and hydrogen peroxide. HeLa cells were untreated (designated C), irradiated with 10 Gy γ-irradiation/α-particles or treated with 150 μM H2O2, and harvested at the time points indicated after treatment and purified histones analyzed by immunoblotting. Red boxes indicate increased levels of histone PTMs, whereas green boxes indicate reduced levels. Shown are representative images acquired from at least two independent experiments, and levels of the respective unmodified histone are shown as a loading control. (A color version of this figure is available at www.redjournal.org.)