PCR and Sanger DNA are two experimental techniques which are often compared. They are similar in two major ways. Both techniques utilize DNA polymerase and template DNA. They vary by what type of nucleotides they use. For example, PCR utilized dNTPs which have a 3' alcohol group available for the extension of the DNA. However, when looking at Sanger sequencing, the alcohol group at the 3' end is missing and replaced with a hydrogen. Therefore, it is unable to extend. The purpose for this is to terminate the DNA sequence. The type of nucleotide that is added to the Sanger sequencing mixture is a ddNTP. Another way that they differ is with Sanger sequencing a fluorescent dye is used. In PCR, no dye is used to determine the amount of amplification.