Recovery of DNA from Low Melting Point Agarose
Low melting point agarose gels should be poured and allowed to set up in the cold room, but electrophoresed at room temperature.
The gels should be stained at 4°C and kept cold until ready to cut out the DNA bands from the gel.
Cut out the DNA bands from the gel with new razor blades.
Use a new razor blade for each band.
Place the agarose pieces into sterile capped tubes (the size of the tubes depends on the volume of the agarose involved).
Add 1X TE buffer to the tubes of agarose (as small a volume as possible, usually about 5X the volume of the gel pieces).
Transfer the tubes to 37°C.
Add an equal volume of buffer-saturated phenol.
The phenol should have been warmed to 37°C.
Centrifuge the tubes at room temperature to separate the phases.
Centrifuge at 10,000 rpm, 10 min in the Sorvall or 5 min in the microfuge.
Transfer the upper aqueous layers to clean tubes.
Add an equal volume of phenol:CHCl3:Isoamyl alcohol (25:24:1) to the tubes.
Mix well and centrifuge at 10,000 rpm, 10 min in the Sorvall or 5 min in the microfuge.
Re-extract the aqueous layer 2X with CHCl3:Isoamyl alcohol (24:1) in the centrifuge as before.
Add 3 M Na acetate to a final concentration of 0.3 M and precipitate the DNAs with 2X volumes of 100% EtOH at -20°C overnight.
Centrifuge the tubes to pellet the DNAs.
Centrifuge in the Sorvall at 10,000 rpm, 10 min, 4°C or 10-15 min at 4°C in the microfuge. 
Wash the DNAs 1X with 70% EtOH in the centrifuge as before and dry the DNA pellets in the vacuum desiccator briefly (10-15 min) to remove the EtOH.
Resuspend the DNAs with a small volume of 1X TE buffer.
Heat the tubes at 65°C for 10-15 min.
Mix well.
