ampure xp beads size selection large fragments

[dinber]

Hi,
I am trying to achieve purification of amplicons which size vary between 500-4000bp.
What is the best ratio of beads : DNA to use for this kind of selection. and do you have any tips (using PEG/isopropanol etc..)?

Thank you,
Dina

[namtran93]

Hello Dina,

I have read a NEB Ultra II library prep kit manual and I found that there was a guidance for your issue. The kit use AMPure XP bead for size selection. Unluckily, they did not give the precise ratio as you request. They said that you can add 20ul or 15ul bead to 96.5 DNA pool to collect 400-700bp DNA fragments. For more information, please read the manual at https://www.neb.com/~/media/Catalog/...anualE7645.pdf.

[Genetic Librarian]

according to this post it should be a ratio of 0.5 or 0.6.

http://core-genomics.blogspot.de/2012/04/how-do-spri-beads-work.html

[Ola]

Thanks for the link. As said above, make sure your buffer is 16% PEG and 0.6M NaCl if you are using it as 1x.