Final answer:
The accurate approach to determine if a plasmid contains a specific gene is to extract the plasmid DNA, use PCR to amplify the gene, and then check for the PCR product's presence on an agarose gel.
Step-by-step explanation:
The correct option is C:
The correct procedure to check if a bacteria with a plasmid contains a specific gene of interest is C. Extract plasmid, PCR, check on gel. Initially, plasmid DNA is extracted and purified from E. coli cells. Next, the Polymerase Chain Reaction (PCR) is performed to amplify the specific gene if present. Finally, agarose gel electrophoresis is used to visualize and confirm the presence of the amplified gene fragment.
Agarose gel electrophoresis enables the separation of DNA fragments based on size. By comparing the pattern of bands on the gel to a known molecular weight marker, one can determine if the gene of interest has been successfully amplified. Samples containing the supercoiled plasmid and PCR products are loaded onto the gel, and if the gene is present, a distinctive band corresponding to the size of the gene will appear.
It is not necessary to ligate or transform the plasmid post-PCR for the purpose of merely detecting the presence of a gene because these steps involve additional cloning processes. Therefore, the best way to identify the presence of the gene of interest is to extract the plasmid DNA, use PCR to amplify the target gene, and finally, check the PCR product on an agarose gel for the appropriate band size.