Question

the oligonucleotide primers used int he polymerase chain reaction are typically 20-30 nucleotides in lenght what primer sequences would you use?

Answer 1

To create primers for PCR, ensure they are complementary to the 3' ends of the DNA template strands, are 20-30 nucleotides in length, and have a calculated melting temperature around 78°C. Taq polymerase is utilized for its temperature stability during the cycling process.

Step-by-step explanation:

To design oligonucleotide primers for a Polymerase Chain Reaction (PCR), you first need the complete DNA sequence of the DNA fragment to be amplified. Primer sequences are typically 20-30 nucleotides in length, but should not exceed 25-45 nucleotides, ensuring that they are complementary to the 3' end bases of both the template strands. Primers should have a melting temperature (Tm) of about 78°C, which can be calculated based on the primer length (N) and the GC content. In PCR, short DNA primers anneal to the DNA template during the cooling phase (55°C) after the DNA strands are separated at a higher temperature (94°C). Taq polymerase is used in PCR because it is stable at these high temperatures and it synthesizes new DNA strands starting from the primer. The PCR cycle includes denaturation, annealing, and extension phases, repeated multiple times to exponentially amplify the target DNA sequence.