Here’s a really easy DNA gel extraction:
1. Go about cutting out your bands of interest in the usual way.
2. Next cut the gel band(s) into tiny cubes.
3. Place tiny cubes in an eppie.
4. Put eppie in -20oC for 15 to 30 min. The idea is to make the band freeze into a mini ice cube.
5. Knock out all of the gel band/cubes onto a 10 (long) x 5 (wide) cm piece of parafilm.
6. Fold the parafilm in half along the length while keeping your gel cubes along the fold in the parafilm. You should have a piece of parafilm folded lengthwise with gel cubes sandwiched between two layers of plastic.
7. Crush/squeeze the liquid out of the tiny cubes. Liquid containing electrophoresis buffer and DNA will separate from the agarose.
8. Collect DNA/electrophoresis buffer mixture with pipet and clean it by ethanol precipitation.
EDIT: Borate in the electrophoresis buffer is a ligase inhibitor. Make sure to thoroughly wash your DNA with 70% EtOH, at least 2 times.