Propargylamino-dCTP is recommended for two-step labeling of DNA e.g. by PCR. It is enzymatically incorporated into DNA as substitute for its natural counterpart dCTP. The resulting Amine-functionalized DNA can subsequently be labeled via the classic Amine/NHS Ester reaction that offers the choice: to introduce a Biotin group (via NHS Ester of Biotin) for subse-quent purification tasks; to introduce fluorescent group (via NHS Ester of fluorescent dyes) for subsequent microscopic imaging.