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Components Of A Typical PCR Reaction Mix (continued). Primers - Oligonucleotides which direct the synthesis of DNA by providing a double stranded region with a free 3’ OH to which dNTPs can be added. Characteristics Of PCR Primers :
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Components Of A Typical PCR Reaction Mix (continued) Primers - Oligonucleotides which direct the synthesis of DNA by providing a double stranded region with a free 3’ OH to which dNTPs can be added. Characteristics Of PCR Primers: Length: 20-30 nucleotides Annealing Temp: Approximately 50oC* Base Composition: Equal Amounts Of Each Base Possess correct directionality Lack of repetitive sequences or runs of the same nucleotide Lack of ability to form secondary structure Lack of ability to form primer dimers Lack runs of 3 or more G’s or C’s at the 3’ end Note: It is essential that the 3’ end of the primer be complementary to the template. This is not true of the 5’ end. Also, when calculating primer annealing temperature, be sure to include only the region that anneals to the template. * Varies with application