Question

If I put two primers which can amplify plasmid and do PCR, and did gel electrophoresis.
If I do gel electrophoresis also with plasmid before PCR , what would be the result compare to the result after PCR. give me the reason and also articles which is related if it is available

Answer 1

The plasmid DNA can take three different conformations including supercoiled, open-circular and linear forms. Therefore in the gel, the plasmid DNA may appear as three different bands. The super coiled conformation is much compact in size than the other forms and therefore it will have less sterric hindrance while moving in the gel. So, the supercoiled form of plasmid will move faster followed by circular and linear forms.

On the other hand, the plasmid will be there only in the linear form after the PCR amplification. Therefore the PCR amplified plasmid will be seen as a single band in the gel. Also, the intensity of the band for the PCR amplified plasmid will be higher as compared to the plasmid sample before PCR amplification.