Question

Flanking primers designed to amplify a gene from an expression vector were mistakenly designed to read outward from the gene instead of towards the gene. What will happen during this particular PCR reaction?

Answer 1

If flanking primers are designed to read outward from a gene instead of towards the gene, the PCR reaction will not produce the desired DNA segment initially. However, subsequent cycles of PCR amplification will synthesize the desired product.

Step-by-step explanation:

Flanking primers that are designed to amplify a gene from an expression vector should be designed to read towards the gene. If the primers are mistakenly designed to read outward from the gene, the PCR reaction will not produce the desired DNA segment.

During the first cycle of PCR amplification, two DNAs will be synthesized: one that starts at the beginning of the desired sequence and the other that ends with the desired sequence.

Both of these sequences extend beyond the DNA of interest. However, during subsequent cycles of PCR amplification, the desired product is synthesized when the primers anneal to the amplified DNAs instead of the original template.