1. Excise the DNA fragment from the agarose gel with a clean, sharp scalpel.
2. Weigh the gel slice in a colorless tube. Add 3 volumes of Buffer QG to 1 volume of gel (100 mg ~ 100µl).
3. Incubate at 50 celcius for 10 minutes (or until the gel slice has completely dissolved). To help dissolve gel, mix by vortexing the tube every 2-3 minutes during the incubation.
4. After the gel slice has dissolved completely, check that the color of the mixture is yellow (similar to Buffer QG without dissolved agarose).
5. Add 1 gel volume of isoproponol to the sample and mix.
6. Place a QIAquick spin column in a provided 2 ml collection tube.
7. To bind DNA, apply the sample to the QIAquick column, and centrifuge for 1 minute.
8. Discard flow-through and place QIAquick column back in the same collection tube.
9. (Optional): Add 0.5 ml of Buffer QG to QIAquick column and centrifuge for 1 minute.
10. To wash, add 0.75 ml of Bufer PE to QIAquick column and centrifuge for 1 minute.
11. Discard the flow-through and centrifuge the QIAquick column for an additional 1 minute at 13,000 rpm (~17,900 x g).
12. Place QIAquick column into a clean 0.5 ml microcentrifuge tube.
13. To elute DNA, add 50 µl of Buffer EB (10 mM Tris-Cl, pH 8.5) or H20 to the center of the QIAquick membrane and centrifuge the column for 1 minute. Alternatively, for increased DNA concentration, add 30 µl elution buffer to the center of the QIAquick membrane, let the column stand for 1 minute, and then centrifuge for 1 minute.