Attached picture of nanodrop result. I used qiagen miRNeasy mini kit to extract RNA . I will use it further for miRNA profiling.
Hello,
High ratios might be due to some dust or dirty in the nano drop stand, so I suggest to clean 3-5 times with a drop of water and repeat the measurement.
Low 260/230 ratio in this case is clearly due to a big contamination of a compound absorbing at 230. It might be sugars, chloroform, phenol... there are multiple possibilitites.
Looking to the picture you uploaded, I would not recommend you to use this miRNA preparation, but to repeat a new one being more careful at the step when potential contaminant (organic separation) might come along during the extraction.
Hello,
High ratios might be due to some dust or dirty in the nano drop stand, so I suggest to clean 3-5 times with a drop of water and repeat the measurement.
Low 260/230 ratio in this case is clearly due to a big contamination of a compound absorbing at 230. It might be sugars, chloroform, phenol... there are multiple possibilitites.
Looking to the picture you uploaded, I would not recommend you to use this miRNA preparation, but to repeat a new one being more careful at the step when potential contaminant (organic separation) might come along during the extraction.
As Cristina notice your sample is carrying some contaminant that absorb at 230 nm and if you want to use it you have to clean it before.
If you have the chance to prepare anther one just do it
bonne chance
Hello Huda,
From your attached NanoSpec photo, you have a good yield of RNA about 73ng/ul and this is a good amount of RNA, but the very low 230 ratios is an indication of organic chemicals contamination like Phenol, or Trizol. Usually, when I use Qiagen kit for RNA which uses column my sample quality is better than the quantity of my RNA, meaning that I will get a very low amount of RNA with a good ratio.
But when I use the old Trizol/Chloroform protocol to extract RNA, sometimes I got low or high reads of my 230 or 260. Dialysis is the good solution to fix this ratios problem. Depends on the volume of your extracted RNA as an example if you have 50ul of RNA. I will use 30ml of 0.1X TE buffer in 100ml Petri dish (This procedure needs to be done in cold temp 4c) so I will do it in a fridge or a cold room (Very Important for RNA). This dialysis membrane is 45mm diameter and pore size is 0.025um. Membrane filters are the circle in shape (Nitrocellulose membrane) which are really good to clean DNA and RNA. Foat the Millipore membrane on the surface of the 30ml of 0.1XTE buffer. Allow the filter to wet for about 5 min. Onto the center of the one dialysis filter, add your RNA sample. Cover the dish and leave it from 2-4 hours in the 4c cold room. After your 2 hours, carfully recover your RNA back to a new fresh tube. Then check your sample on the nanoSpec again and you will notice the diffrent in your sample ratios.
230 nm absorption is mostly due to The buffer itself. To avoid use The elution buffer as your blank.
a good 260/280 ratio means your sample is free from protein contaminants, however your 260/230 is low, which shows that there are nucleotide contaminats. most probably your sample is degraded. try running a gel to see if the size of your sample is right. if the size is correct, maybe your RNA has buffer or ethanol contamination. then u need to prepare fresh sample.
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