PE adapter concentration

[gwilkie]

Does anyone happen to know the concentration of the Illumina PE adapters?

I would like to calculate the amount of adapter to add to ligations where I have less than the recommended amount of A-tailed library DNA, in order to maintain the ratio at 10:1 or 20:1. However the concentration of the adapter mix is not stated!

I have the same problem with the Agilent InPE (index paired end) adapter mix for SureSelect - I cannot find the concentration of the adapter mix.

Thanks,
Gavin

[pmiguel]

Previous threads on this topic put the concentration of Illumina DNA prep kit adapters (both the older method and the newer TruSeq) at 15 uM. See here and here.

Further, the former thread contains evidence that the adapter concentration is 30-fold lower for the TruSeq RNA prep kit.
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Phillip

[gwilkie]

Thanks, I thought it might be that but wasn't certain.
Agilent refused to say what the adapter concentration was - proprietary info apparently
I should be able to compare the Illumina and Agilent versions and see if they are similar.

[pmiguel]

Unless I am missing something, you could just check the concentration on a spectrophotometer. If you have a nanodrop, it would only cost you 1 ul. All the normal caveats with UV spectrophotometric measurements of DNA apply, of course. But, unless Agilent is deliberately attempting to conceal the concentration, you should be able to get an approximation that way.

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Phillip