Scroll down this screen to see the steps for digesting a DNA sequence with multiple enzymes, and running a gel.
1. Assume that we have already used the 'DNA' button (or menu) to open the T7 bacteriophage DNA sequence (in the 'T7 mapping' folder), and have also already used the 'Enzyme' button (or the Site menu) to open up two restriction enzymes - Nru I and Bcl I.
2. To digest this sequence with both enzymes, hilight both enzymes by clicking the first enzyme name, holding down the shift key, and clicking the second enzyme name, as shown below.
3. To digest the DNA sequence with both enzymes simultaneously (double-digestion), hold down the shift key again and click the 'Cut DNA' button...
4. Two new lines are generated. The first represents a single-digestion of the DNA with Nru I, and the second line (the one highlighted below) represents the double-digestion with Nru I and Bcl I. Click on that line to highlight it, as shown below...
...and load the double-digestion into the first well by clicking the 'Load' button, as shown below.
5. Now click on the third line (the single-digestion of the DNA with Nru I)...
...and load it into the second well (select the second white well button before clicking the 'Load' button). Note in the graphic below that the 'Loaded' window is keeping track of what has been loaded into each well.
6. One additional single-digestion needs to be done. Click the first line to activate the original undigested DNA sample...
...then click the third line to activate the enzyme Bcl I.
7. Click the 'Cut DNA' button (or use the Cut/find menu) to perform this single-digestion...
...and then load it into the third well.
8. Finally, click the 'Run' button (or use the Run menu) to run the gel. It should look like the graphic below, at the default settings of 100 volts and 1.0% agarose. Note that we have also clickted the purple button below the gel, to stain the fragments to make them visible.
9. Click here to go back to the "other features" menu, or else click the "Next" button to see the next feature...