RNA isolation with TRizol - basic Q (May/19/2005 )

Hi everybody,
Can anyone tell me more about what happens during RNA isolation using TRizol, chloroform, phenol and ethanol. And what forms the supernatant and interface?
Thanks millions in advance

Ribosoul

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Hi

Trizol (and related products) tell you what is in the supernantant at each step. Typically though, trizol contains phenol in, so at the first separation step the superantant should contain RNA, and the interface should contain protein, while the lower phase should contain DNA and protein. Same for chloroform step.

bob

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I understand phenol is for denaturing protein (guanidinium thiocyanate included in TRIZOL as well)
Chloroform is for dissolving lipids and denaturing protein.
Isopropyl alchol is for precepitating RNA
75% EthOH is for dissolving salts and organic solvents.

Absolute EthOH is for precepitating DNA after RNA is removed with 3-propanol.

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hi
agree with bob1 and vagrants. I would add the fact that adding chloroform increases the efficiency of phases separation as it's more hydrophobic than phenol.

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