PCR q's

• 3 phases of thermal cycler: denaturation, annealing, extension
• Denaturation – separates DNA strands at high temperatures
• Annealing – allows primers to bind to the first several bases at the beginning of each strand of target sequence
• extension – Taq polymerase copies rest of ssDNA segment
• Explain why a reverse transcription step is necessary

  • Needed to convert RNA to DNA so the fluorescent dye may attach after successful duplication
  • fluorescent dye cannot directly bind to the RNA strands
  • this intermediate step is needed to convert RNA to DNA
  • in addition, RNA must be converted to DNA, as PCR works by replicating specific DNA sequences
• Know what part of a virus is detected by PCR

  Nucleic acid or genetic material