Practice question
Question
Which sequencing method produces light after nucleotide incorporation?
Explanation
Pyrosequencing is a non-electrophoretic sequencing-by-synthesis platform that couples nucleotide incorporation to visible light production. Each cycle dispenses a single dNTP; if it is complementary to next template base, DNA polymerase incorporates it and releases inorganic pyrophosphate, PPi, stoichiometrically. ATP sulfurylase converts PPi to ATP, which drives firefly luciferase to oxidize luciferin emitting photons. Light intensity indicates incorporation and number of same bases in homopolymer runs. Sanger uses termination fluorescence, Ion Torrent measures pH change, and Maxam-Gilbert relies on chemical cleavage without light.