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paraffin from ffpe tissue samples refuse to dissolve in xylene - DNA extraction from ffpe tissue shavings (Mar/30/2011 )

Hello
I'm trying to extract DNA from FFPE tissue shavings. I'm using xylene to disolve the paraffin but after several incubations and washes with it, the wax refuses to dissolve.
I was wondering if it is safe for the tissues to leave them in xylene overnight? and/or if there is a better protocol for it.
Thank you

-linmicro-

How big are the slices and how much xylene are you leaving in them?

we use 10ml of xylene for a 10umicron slice and leave it shaking overnight.

-PostDocTrauma-

PostDocTrauma on Thu Mar 31 15:33:34 2011 said:


How big are the slices and how much xylene are you leaving in them?

we use 10ml of xylene for a 10umicron slice and leave it shaking overnight.

I have samples weighting between 50 and 60 mg (tissue plus wax) in eppendorf tubes. These are pieces that were shaved from a block of ffpe tissue.
I'm using 2mls of xylene to dissolve the paraffin, because a protocol that I'm following calls for 1ml of xylene to be used in 25 mg of ffpe tissue sample.
But I might need to use more xylene according to what you mentioned.
Thank you so much for your answer and help

-linmicro-