Problem
You have liquid culture of bacteria carrying a plasmid. However, you are not sure if this plasmid contains the xyz gene. The size of the xyz gene is known.
1) What order of techniques should you perform to confirm for the presence or absence of the xyz gene in the plasmid?
a) Plasmid isolation, ligation, gel electrophoresis
b) Plasmid isolation, gel electrophoresis
c) Plasmid isolation, PCR, gel electrophoresis
d) Plasmid isolation, digestion with BamHI, gel electrophoresis
e) Plasmid isolation, PCR, transformation
2) In one sentence, explain why you cannot perform gel electrophoresis on the undigested plasmid to determine its size.