Primers
A primer is a short string of nucleotides used in the synthesis of DNA. Primers are essential for the function of DNA polymerase as the enzyme can only build nucleotides onto an existing DNA strand. They are synthesised by an enzyme called Primase and are complementary in bases to the single stranded DNA template with a 3' OH end[1]. Primers are also useful in the polymerase chain reaction (PCR) for the amplification of a particular gene of interest. Primers are short RNA molecules in living cells, however, DNA serves as the primer in non-living cells (in vitro) such as in PCR[2]. DNA polymerase I plays an important role in the replication process by the removal of the RNA primer during its proof reading activity[3].