Question

A restriction map lists the locations of DNA sequences that are cut by a particular restriction enzyme for a piece of DNA, such as a chromosome or a plasmid. Restriction maps are important when generating a construct for experimental use. Digesting the DNA sequence with the restriction enzymes will result in fragmented DNA of predictable sizes, based on the restriction map, that allow a researcher to analyze if his or her construct was generated correctly when visualized using gel electrophoresis. Use the linear restriction map below to predict where you would expect to see bands on a gel if a digest is performed using the specified restriction enzymes. Assume that there is enough restriction enzyme that every possible restriction site on each molecule of DNA will be cut.

Answer 1

Single digestion with EcoRI gives three fragments of sizes 10, 18, and 14 kb respectively.

Single digestion with XbaI gives four fragments of sizes 6, 12, 20, and 4 kb respectively

Double digestion with both the restriction enzymes gives fragments of following sizes:

* 6 kb fragment (0 - 6 kb region)

* 4 kb fragment (6 - 10 kb region)

* 8 kb fragment (10 - 18 kb region)

* 10 kb fragments - 2 (18 - 28 kb region, 28 - 38 kb region)

* 4 kb fragment (38 - 42 kb region)

Size markers EcORI Xbal EcoRIXba 20kb l6kb 14kb 12kb 0kb 8kb 6kb 4kb