US 7,488,579 B2
Methods and compositions to extract DNA, RNA and protein simultaneously from biological samples
Xiaoliang Han, San Francisco, Calif. (US); Zhongdong Liu, Newark, Calif. (US); and Jinming Xia, San Francisco, Calif. (US)
Assigned to BioChain Institute, Inc., Hayward, Calif. (US)
Filed on May 05, 2004, as Appl. No. 10/839,905.
Claims priority of provisional application 60/468555, filed on May 06, 2003.
Prior Publication US 2004/0224344 A1, Nov. 11, 2004
Int. Cl. C12Q 1/68 (2006.01)
U.S. Cl. 435—6 14 Claims
 
1. A method of isolating DNA, RNA and protein simultaneously from biological samples comprises:
a) extracting DNA, RNA and protein simultaneously from the biological samples with extracting solutions comprising pH from 9.5 to 10.5 extraction reagent, wherein the extraction reagent comprising phenol and a buffer with pH from 9.5 to 10.5;
b) separating the solutions containing said DNA, RNA and protein from step a) into an upper aqueous phase, a lower organic phase and an inter-phase there between to recover a DNA and RNA mixture from the upper aqueous phase, wherein said DNA and RNA mixture is substantially protein-free, and said upper aqueous phase has pH about 9.5 to 10.5;
c) separating the DNA and RNA mixture into separated DNA and RNA by selective precipitation and/or selective enzyme digestions;
d) recovering the separated DNA and RNA for applications;
e) extracting protein from the lower phase wherein said protein is substantially free of DNA and RNA; and
f) Obtaining six classes of different specimens wherein said specimens are DNA and RNA mixture; substantially pure RNA without undergoing DNase treatment; substantially pure DNA without undergoing RNase treatment; substantially pure RNA obtained after DNase treatment; substantially pure DNA obtained after RNase treatment; and protein pool with full representing population of different proteins contained in said biological samples.