Final answer:
Primer length refers to the number of nucleotides a primer contains and is important for initiating DNA amplification.
Step-by-step explanation:
The length of a primer is the number of nucleotides it contains. In the context of DNA amplification techniques like PCR (Polymerase Chain Reaction), primers are short DNA strands that are synthesized chemically and are complementary to the target DNA sequence.
Primers are crucial for initiating the amplification process. According to the reference provided, primer length should be between 25-45 nucleotides. This range ensures that the primers are long enough to bind specifically to the target DNA but not too long to cause nonspecific binding.