Covaris and 454 rapid libraries

[TonyBrooks]

Hi all
Has anyone any experience of preparing 454 rapid libraries after shearing with the Covaris?
We've generally used the 400bp settings (Duty Cycle:10%, Intensity:4, Cycles/burst:200, Time:55 seconds) before and produced excellent 700bp libraries. However, recently we've seen out libraries come out at lower yield and around 1kb.
Does anyone have any optimised settings for Covaris shearing on genomic DNA?
Thanks
Tony

[Aniki]

Hey, I seem to have the same issue. Were you able to find a solution to this?

Your help is greatly appreciated!

[Hamid]

Hi Tony,

Do you run the sheared samples on a bioanalyzer prior to any cleanup or size selection step? It is important to have that so as to exclude any variables introduced as a result of cleanup and size selection.

Thank you

Hamid