6 replies to this topic

[molcyt]

Hi every one,

I checked my RNA purity and 260/230 ratio is between 0.67-2.17. I want to clean my RNAs, do you have any advice about that, any kit I can use? Thanks

[sarah]

Hi,

I assume you mean 260/280 ratio  

The Qiagen RNeasy kit is very good:)

sarah

[molcyt]

No, I mean the ratio of 260/230.  Also, I isolated my RNAs using Qiagen RNeasy kit.

Edited by molcyt, 18 February 2005 - 09:22 AM.

[bob1]

260:280 ratio is a better measure of the purity of the sample.

Bob

[jadefalcon]

Rna or Dna that comes of columns after correct purification is very clean in my experience.... you just have to ensure that no EtOH containing buffer contaminates you eluate, then everything should be ok!

mike

[fred_33]

hi
the ratio 260/280 should be up than 1.8 for good purity of prep, but a too high ratio (i mean >2) is also negative... But if you really mean 260/230, your ratio should be greater than 1.8 too.
see for this ratio this topic http://www.protocol-...?showtopic=4476

In such cases, i usually do a complementary pehonol/chlo at pH 4.7, with good ethanol wash and good drying of ethanol.
But jadefalcon is right.
fred

Edited by fred_33, 24 February 2005 - 04:32 AM.

[badcell]

The absortion at 230 is due to organic compounds such as Trizol. In your case, as you've been using columns for RNA extraction I would say that the problem is the ethanol, as jadefalcon said. Maybe you only need to dry your samples a bit more.