Plasmids are pieces of DNA that contain recognition sites where restriction enzymes cut plasmid.
To separate and find out the length of fragments cut by restriction enzymes, scientist use a technique called gel electrophoresis. During gel electrophoresis, fragments with smaller size move faster while those with bigger size move slower.
A connected circle with 'x' number of recognition sites gets broken into 'x' pieces while a linear strand with 'x' number of recognition sites gets broken into 'x-1' pieces.
With different combinations of restriction enzymes in different lanes, and assuming that everything runs smoothly, there are no overlapping bands, and so on:
- The length totals for each lane must…
- The number of bands in a multi-enzyme lane (such as A+B) must …
- The longest fragment in a multi-enzyme lane cannot be …
If you want a printer-friendly version of this module, you can find it here in a Microsoft Word document. This printer-friendly version should be used only to review, as it does not contain any of the interactive material, and only a skeletal version of problems solved in the module.
Copyright University of Maryland, 2007
You may link to this site for educational purposes.
Please do not copy without permission
requests/questions/feedback email: firstname.lastname@example.org