Biochemistry PCR is a cell-free test tube method for amplifying a target sequence of DNA. Which of the following is not required for PCR? A Taq polymerase B d-NTP C Primer D Radiolabeled DNA probe 💡 Explanation PCR is a cell-free test tube method for amplifying a target sequence of DNA. Which of the following is not required for PCR? ✓ Correct Answer: D. Radiolabeled DNA probe