Answers
1) In the uncut lane, Au has 3 bands (one being the intense) and PU has 2 bands (one being the intense). If there are more than one band, one possibility is- it is a plasmid DNA. Plasmid dna runs with multiple bands- nicked, linear and supercoilled.
2) The uncut DNA is electrophoresed because it serves as a control when you run a cut DNA with enzyme on a gel
3) When the know sample of pBR322 was cut with enzyme 1 it showed multiple cuts- 3, 2 and 1.3 Kb while when it was cut with enzyme 2, it did not show any cut.
4) The sizes of the band I can actually see when pBR322 is cut with enzyme 1- 3, 2.6, 2 amd 1.3 Kb
5) The anamolous band might be 3 and 2.6 Kb fragment which has arisen from uncut plasmid.
6) Yes the plasmid which is isolated is pBR322 because the unknown DNA shows same band pattern when cut with enzyme 1 and 2 except the 3 and 2.6 Kb band which might be a result of uncut or partially cut.
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