DTTP
From The School of Biomedical Sciences Wiki
dTTP is one of the five deoxynucleotide triphosphates (dNTPs), it stands for Thymidine triphosphate.
One use for dTTP is when performing the Polymerase Chain Reaction (PCR), which is used to amplify a piece of DNA. dTTP is added to the mixture with the other dNTPs and these nucleotides are used to form a complementary strand of DNA by Taq Polymerase.