260/230 values of RNA and precipitation of RNA

[newbie17425]

Hello again,

 

I have extracted RNA and i am satisfied with the purity (260/280 ratio) and the yield. What is troubling me is the very low 260/230 ratio? Therefore, i wanted to know how important is the 260/230 ratio in RNA extraction. I will use the RNA for qPCR.

 

Yield 26-35 ng/ul and 260/280 ratio is between 1.9-2.2

 

If i want to re-precipitate the RNA should i use sodium acetate or Lithium chloride to do this?

 

Thanks

[CharonY]

It depends on what you extracted and how. If you used Trizol, or are doing phenol extraction there is a good chance that that is the absorbing substance.

Other typical things include humic acids (soil and sediment), peptides, a number of aromats and urea on top off my head. For clean up I would existing lab protocols based on you extraction method. That makes it easier to compare issues within your lab for your particular type of samples.

[newbie17425]

It depends on what you extracted and how. If you used Trizol, or are doing phenol extraction there is a good chance that that is the absorbing substance.

Other typical things include humic acids (soil and sediment), peptides, a number of aromats and urea on top off my head. For clean up I would existing lab protocols based on you extraction method. That makes it easier to compare issues within your lab for your particular type of samples.

i am using a kit for extraction. Our lab doesn't have any clean up kit.

[CharonY]

Your extraction protocol does have a cleanup step (typically precipitation with washing of the pellet or affinity based immobilization followed by washing). There is no optimal protocol for every sample, usually a lab adapts one or a few standardized protocols as the basis and make adjustments as necessary.