Question

Which of the following would be an appropriate sequence of temperatures for PCR? ______

A) 94°C, 65°C, 72°C
B) 65°C, 72°C, 94°C
C) 72°C, 65°C, 94°C
D) 94°C, 37°C, 55°C
E) 94°C, 55°C, 37°C

Answer 1

The appropriate sequence of temperatures for PCR is A) 94°C, 65°C, 72°C, which correspond to denaturation, annealing, and extension steps, respectively. Incorrect annealing temperatures can hinder primer binding and reduce the specificity and yield of the PCR amplification product.

Step-by-step explanation:

The appropriate sequence of temperatures for a Polymerase Chain Reaction (PCR) should correspond to the three main steps involved in the process: denaturation, annealing, and extension. The correct answer to the sequence of temperatures for PCR is A) 94°C, 65°C, 72°C. During the PCR cycle, the temperatures serve the following functions: 94°C is the denaturation temperature to separate the DNA strands, 65°C as the annealing temperature for primer attachment, and 72°C as the extension temperature optimal for Taq polymerase activity.

Having the incorrect annealing temperature, such as 65°C instead of the usual 50°C to 55°C, could lead to inefficiency in primer binding, reduced specificity, and a consequent drop in the yield of desired amplification product. This demonstrates the importance of closely following PCR protocols to achieve successful DNA amplification.