Question

Question #25338

Answer 1

I think that the program uses a wrong temperature and exposure period for the first step in the process of DNA copying by polymerase chain reaction, or PCR.

In order, the steps that must be taken in order to obtain a successful amplification are:

• Denaturation
• Annealing
• Primer extension (or elongation)

Each of these steps require a certain temperature and a certain exposure time for the DNA sample. The first step, denaturation, is what braks the DNA double-helix and forms single-stranded DNA molecules.

This is actually done by heating the template to a temperature of `"94 - 98"^@"C"` - usually `95^@"C"` - for a period of 20, maybe 30 seconds. This will result in the breaking of the hydrogen bonds that keep the DNA double-helix together.

As you can see, your program uses a temperature of `50^@"C"` for a period of `"1 minute"` for the denaturation step, which will undoubtedly make the process unsuccessful. The other temperatures and times of exposure given are consistent with what a correct program would look like.

Check out this great video on DNA copying by PCR: