DNA	> ISOLATION OF DNA FRAGMENTS	> Elution of DNA from Agarose Gels - Glassmilk Method
		> Elution of Small Fragments of DNA from Agarose Gels(<500bp)
		> Gel Purification of DNA from Agarose Gels by Centrifugation

 

Gel Purification of DNA from Agarose Gels by Centrifugation

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1. Gel purify DNA fragment on 1% agarose and excise band under UV transilluminator. Always wear eye protection when using the transilluminator as UV light is harmful to your eyes.
2. Dry the gel slice on 3M paper for a few min. To remove excess buffer.
3. Place the gel slice into a Pharmacia microspin column (these are designed to fit into microfuge tubes)
4. Place this column into a microfuge tube (1 mL size) and spin at ~3000 g (5000rpm in Hermle tabletop) for 45 sec.
5. The DNA is recovered in the eluate.  It can be used directly in ligation reactions.  Alternatively if you add ammonium acetate and ethanol precipitate it will probably ligate more efficiently.

Recoveries:

greater than 5000bp ~ 50%

less than 2000bp ~ 80%

best for DNA fragments smaller than 500bp

Reference: GATA 9:31-33, 1992. (He et. al.)