Final answer:
In pyrosequencing, ddNTPs are not used; instead, the method relies on enzymes and other reagents like primers, dNTPs, luciferase, and a DNA template.
Step-by-step explanation:
Among the listed reagents, ddNTPs (“dideoxynucleotides”) are NOT used in pyrosequencing. Pyrosequencing relies on the release of a pyrophosphate during DNA synthesis when a nucleotide is incorporated. It uses enzymes such as DNA polymerase for adding nucleotides, luciferase for light generation, and distinct reagents such as primers and a DNA template.
In contrast, ddNTPs are used in Sanger sequencing, another DNA sequencing method, where their incorporation terminates DNA chain elongation, allowing determination of the DNA sequence through capillary electrophoresis. Pyrosequencing utilizes the sequential addition of dNTPs to detect the sequence based on a series of enzymatic reactions that produce visible light proportional to nucleotide incorporation, thus eliminating the need for ddNTPs.