Obtaining DNA from formalin fixed tissue

s.pritchard mmd280 at sysc.abdn.ac.uk
Mon Aug 18 10:15:04 EST 1997

W.T Howson (whowson at julian.uwo.ca) wrote:
: Does anyone out in this group have any experience in obtaining DNA from
: formalin fixed/parrafin embedded tissue.  We have tried two methods,
: proteinase K treatment and a modified Qiagen tissue kit after removing
: the parafin using standard technique and appear to get no DNA from these
: tissues. Are we doing something wrong or is there a more reliable and sure
: method available.

: thanks

The fixation of the material may vary.Too little or too much fixation is not
good for DNA extraction .try getting recently fixed tissue and extract DNA from
it. I used a standard proteinase K protocol (0.1% SDS at 37oC overnight or 55oC
for 4 hours followed by 80oC for 5-10 mins to inactivate PK).
I evaluated different protocols using some fairly recent sections that were
available in the lab and all the protocols worked (the above appearing to be the
best ) However when I tried extracting from my actual samples I got
nothing.After repeating it and trying all the other protocols with no result I
concluded that it must be my sections that were the problem.therefore I got some
sections cut from more recently fixed tissue and hey presto it worked! When my
samples were replaced with more recent tissue they worked too.
Hope this helpful and good luck

More information about the Methods mailing list