A purified DNA preparation of a certain plasmid is digested to completion with BamH1 restriction endonuclease.In separate reactions,the same preparation was digested to completion with EcoRI and with a mixture of EcoRI and BamH1,respectively.The diagram below shows the appearance of the original molecules and the digestion products in the three digestion mixtures,after separation by electrophoresis in an agarose gel.
Lane M-linear DNA markers of the indicated length in kb
Lane 1-sample of original plasmid DNA preparation
Lane 2-sample of the products of BamH1 digestion
Lane 3-sample of the products of EcoRI digestion
Lane 4-sample of the products of digestion of BamH1 + EcoRI
Answer and justify the following:
a)What was the original DNA molecule's length?
b)Was the original plasmid DNA circular or linear?
c)How many restriction sites for EcoRI and BamH1 did the original plasmid have?
d)Draw the original plasmid,using B and E to indicate the location of the BamH1 and EcoRI restriction sites.Indicate the number of kb between sites.

Question

A purified DNA preparation of a certain plasmid is digested to completion with BamH1 restriction endonuclease.In separate reactions,the same preparation was digested to completion with EcoRI and with a mixture of EcoRI and BamH1,respectively.The diagram below shows the appearance of the original molecules and the digestion products in the three digestion mixtures,after separation by electrophoresis in an agarose gel.
Lane M-linear DNA markers of the indicated length in kb
Lane 1-sample of original plasmid DNA preparation
Lane 2-sample of the products of BamH1 digestion
Lane 3-sample of the products of EcoRI digestion
Lane 4-sample of the products of digestion of BamH1 + EcoRI  
Answer and justify the following:
a)What was the original DNA molecule's length?
b)Was the original plasmid DNA circular or linear?
c)How many restriction sites for EcoRI and BamH1 did the original plasmid have?
d)Draw the original plasmid,using B and E to indicate the location of the BamH1 and EcoRI restriction sites.Indicate the number of kb between sites.

Quizplus · Accepted Answer

The Answer of A purified DNA preparation of a certain plasmid is digested to completion with BamH1 restriction endonuclease.In separate reactions,the same preparation was digested to completion with EcoRI and with a mixture of EcoRI and BamH1,respectively.The diagram below shows the appearance of the original molecules and the digestion products in the three digestion mixtures,after separation by electrophoresis in an agarose gel.
Lane M-linear DNA markers of the indicated length in kb
Lane 1-sample of original plasmid DNA preparation
Lane 2-sample of the products of BamH1 digestion
Lane 3-sample of the products of EcoRI digestion
Lane 4-sample of the products of digestion of BamH1 + EcoRI  
Answer and justify the following:
a)What was the original DNA molecule's length?
b)Was the original plasmid DNA circular or linear?
c)How many restriction sites for EcoRI and BamH1 did the original plasmid have?
d)Draw the original plasmid,using B and E to indicate the location of the BamH1 and EcoRI restriction sites.Indicate the number of kb between sites.

A Purified DNA Preparation of a Certain Plasmid Is Digested