Where do scientist obtain primers to be used in pcr and in this technique

Scientist obtain the primers from the DNA polymerases that preform the synthesis which must have an existing strand of nucleotides already in order to attach new DNA nucleotides. The existing strand of new DNA nucleotides is the primers

Explanation:

In order to happen DNA synthesis of a wanted portion of DNA in laboratory,

Scientist obtain the primers from the DNA polymerases that preform the synthesis which must have an existing strand of nucleotides already in order to attach new DNA nucleotides. The existing strand of new DNA nucleotides is the primer. To that existing strand of nucleotides we call primer. In a lab, scientists produce DNA primers through specific sequences that bind to other sequences of a single-thread DNA molecule and these are the primers commonly used to perform PCR.

oxygen = 21% of the atmosphere

nitrogen = 78%

carbon dioxide = 0.1%

argon =0.934%