Transparent pellet - (Nov/10/2007 )

Hey guys,

I am just curious to know why i get a transparent pellet sometimes after ethanol precipitation and 75% ethanol wash, and sometimes a regular white pellet even after following a same protocol? What exactly is the cause for this and does it effect the subsequent applications? Does it signify the poor or good quality of RNA or DNA?

thanks a ton in advance.

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I'm not 100% sure about this, but I'd say it might have to do with salt content. More salt, whiter the pellet...
Then again, maybe I'm just being stupid, so do check it with someone who's sure about it

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Hi

l 'm n't sure, wheather ur DNA contant is very low or nil. sometimes if U use sodium salts also give transparent (little PPt)

Siva

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May be there might have been differences in the total DNA in the samples. Higher amounts of DNA is better visible than lower amounts.

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Thanks for your replies guys. I found out that the transparency of the pellet doesnt interfere with the downstream applications. I was able to rt, pcr amplify the pellet successfully. I also read somewhere that more transparency of the pellet indicates higher purity. But i am not sure.

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I know that's true for ice, ha.

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in my experience, transparency equals purity, as the whiteness is given by salts. the more transparent your pellet, the cleaner you DNA/RNA

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Just to add to this, I've become a bit of an expert at DNA preps, and often the pellet of even a midiprep will be pretty much invisible. If you're even doing any form of alcohol precipitation and don't see a pellet, just keep going. You may be pleasantly surprised with the outcome.

Ginger

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No doubt! Some of my cleanest and highest DNA yields came from preps where I couldn't see a pellet at all. I almost stopped thinking I wasn't going to have a yield. Now I always carry preps out to the end and test the yield on a gel and 260/280 absorbance.

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