DNA/RNA Extraction from the Same Material

A protocol / method / schedule /procedure for extraction / isolation of both DNA and RNA from the same material typically plant leaf / leaves

1） Take one medium sized leaf or half a large leaf （5 to 20 cm^2）， weigh and freeze in liquid nitrogen.

2） Grind the tissue in a bleached and baked pestle and mortar with liquid nitrogen.

3） Transfer the powder produced to a l5ml Falcon blue cap tube. Add 2 ml of homogenization buffer （4 ml per g） and disperse the tissue in it.

4） Leave for 10 min at room temperature.

5） Add 2 ml of phenol/chloroform and vortex.

OR,

1） Put a small or medium sized leaf into a 4“ x 6” 500 guage （thick!） plastic bag.

2） Add 2-3 ml homogenization buffer （you may need more for large leaves） to the bag.

3） Grind the leaf inside the bag using the top end of a 50 ml corex tube.

4） Pour the homogenate immediately into a 15 ml Falcon blue cap tube containing equal volume of phenol/chloroform then vortex.

5） Goto step 6

6） Spin for 10 min at 2,500 rpm in a bench centrifuge.

7） Transfer 0.7 ml of the aqueous phase to an Eppendorf tube, add 0.7 ml phenol/chloroform, vortex and spin for 5 min.

8） Transfer 0.6 ml of the aqueous phase to a fresh Eppendorf tube, add 0.6 ml phenol/chloroform, vortex and spin for 5 min.

9） Transfer 0.5 ml of the aqueous phase to a fresh Eppendorf tube, add 0.5 ml chloroform/isoamyl alcohol, vortex and spin for 5 min.

10） Add 4M LiCl to the final conc. of 2M and leave for several hrs at 4℃ （better o/n）。 Spin for 10-15 min. RNA should be in a pellet. Remove supernatant and precipitate the DNA with ethanol.

11） Treat RNA fraction with DNase RNase-free, and the DNA fraction with RNase-free of DNase.

Notes:

then add 0.1 mg/ml proteinase K

Pat Heslop-Harrison University of Leicester December 2003.

（I'm afraid I did not note the source of this protocol.）