Western blot detection of cyclin A phosphorylation using A-431 cells treated with EGF. Blots were probed with cyclin A (H-432): sc-751 (A), p-cyclin A (Ser 154)-R: sc-12916-R preincubated with cognate phosphorylated peptide (B) and p-cyclin A (Ser 154)-R: sc-12916-R pre-incubated with cognate unphosphorylated peptide (C).