Table 1. Chemical structures and optical characteristics of Cy3 and Cy5 analogues, I (Cy3a+, Cy5a+, Cy3a1±, Cy5a1±, Cy5a2±, Cy5a3±, Cy3a−, Cy5a−, Cy3, Cy5), and their corresponding fluorescently labelled deoxyuridine triphosphates, II (dU(Cy3a+)TP, dU(Cy5a+)TP, dU(Cy3a1±)TP, dU(Cy5a1±)TP, dU(Cy5a2±)TP, dU(Cy5a3±)TP, dU(Cy3a−)TP, dU(Cy5a−)TP, Cy3-dUTP, Cy5-dUTP), measured in PBS buffer (0.15 M NaCl, 10 mM potassium phosphate, pH 7.4).