Phosphoamino acid analyzed by capillary electrophoresis. A, Electropherogram of the hydrolyzed unphosphorylated NtCaMK1 with FITC labeling. B, Electropherograms of the hydrolyzed autophosphorylated NtCaMK1 with FITC labeling. a, Whole electropherogram; b, electropherogram intercepted from a and c; c, electropherogram with addition of standard P-Thr to phosphorylated NtCaMK1 sample to indicate phosphorylated Thr residue.