Hi there,

From the first digest (BamHI+BglII) starting from a circular DNA, one can say there are two sites. Comparing other digests where BamHI and BglII are exchanged, one can conclude that both enzymes are cutting (maps are modified when switching from one to the other). Therefore BamHI and BglII are cutting once : sites are separated by 0.8kb  on one side and 3kb on the other. Going to the second and third digests : BglII and BamHI are linearizing the plasmid so KpnI is cutting twice to generate three fragments. And identically from the fourth and fifth digests, one can conclude that EcoRI is cutting three times in order to generate 4 fragments. All you have to do now is to place these 5 cleavage sites towards BamHI and BglII sites in order to get the expected  fragment sizes. So it's a matter of geometry! The main trick is that the 0.8kb fragments generated in the two first digests can't be the same (ie having the same ER site at their extremities)... And it is the same concerning the 0.3kb fragment in the third and fifth digests... I enclose the final map.

Hi there,

From the first digest (BamHI+BglII) starting from a circular DNA, one can say there are two sites. Comparing other digests where BamHI and BglII are exchanged, one can conclude that both enzymes are cutting (maps are modified when switching from one to the other). Therefore BamHI and BglII are cutting once : sites are separated by 0.8kb  on one side and 3kb on the other. Going to the second and third digests : BglII and BamHI are linearizing the plasmid so KpnI is cutting twice to generate three fragments. And identically from the fourth and fifth digests, one can conclude that EcoRI is cutting three times in order to generate 4 fragments. All you have to do now is to place these 5 cleavage sites towards BamHI and BglII sites in order to get the expected  fragment sizes. So it's a matter of geometry! The main trick is that the 0.8kb fragments generated in the two first digests can't be the same (ie having the same ER site at their extremities)... And it is the same concerning the 0.3kb fragment in the third and fifth digests... I enclose the final map.

I'm not sure if I understand your question, but if you have the sequence, tools like A Plasmid Editor (ApE) are very helpful for visualizing restriction digest and band sizes etc. Here is a link to the website where you can download it for free!

http://biologylabs.utah.edu/jorgensen/wayned/ape/

Hi, Dominique just answered you but to add a little more help:

http://en.wikipedia.org/wiki/Restriction_map

https://www.youtube.com/watch?v=8FqMUF96cPE

this will b the model