dGTP, or deoxyguanosine triphosphate, is a nucleotide triphosphate commonly used as a reagent in PCR (polymerase chain reaction). PCR is a widely used technique in molecular biology that allows for the amplification of specific DNA sequences.

dGTP, along with the other three nucleotides (dATP, dCTP, and dTTP), are added to the reaction mixture in order to provide the necessary building blocks for the extension of the primers. The incorporation of dGTP into the growing DNA strand is detected by fluorescent probes or other detection methods, allowing for the quantification and analysis of the amplified DNA.