The present invention relates to nucleic acid sequencing methods, kits and reagents, and more particularly to methods of sequencing nucleic acid which employ a nucleic acid processing enzyme and one or more nucleotide analogues that are capable of binding to the active site of the enzyme and to complementary bases in the nucleic acid molecule being sequenced, but which are non-incorporable or inhibitors of the nucleic acid processing enzyme. In further aspects, the present invention relates to conjugates which comprise a deoxyribonucleotide triphosphates (DNTPs) or an analogue thereof linked to an intercalating dye.