DNA form FORMALIN fixed specimens

Guy Reeves R.Guy.Reeves at ncl.ac.uk
Fri Apr 28 08:07:34 EST 1995


Hi 
I am about to attempt to amplify DNA from 
formalin (= formaldehyde) preserved biological 
specimens as all ( as far as I am aware) 
previous protocols have been unable to amplify 
DNA fragments via PCR of more than 200bp 
(except in the rare circumstances where the 
formalin was phosphate buffered) I am looking 
for novel approaches.
I am starting form the premise that the DNA, 
contrary to popular belief, is not significantly 
degraded in size by the fixation process, but the 
difficulties in 200bp+ amplifications result form 
the formation of formalin catalysed protein 
DNA cross-linking, which DNA polymerases 
are unable to read through. A recent paper 
provides compelling evidence, in my humble 
view, that is the case (listed below).  I am 
therefore looking for novel approaches to 
preferentially disrupt covalent DNA protein 
cross links without destroying/modifying the 
DNA molecules.  I got a few ideas though I  
fear they lack sound chemical reasoning.  
I would very much like to talk to anybody who, 
either has experience of amplifying from 
formalin preserved specimens or equally 
anybody with knowledge of protein -DNA 
interactions and would be willing to give me 
there opinion of what might work and what will 
not.
  
If  it does prove feasible to readily and cheaply 
amplify form preserved museum specimens it 
would be a extremely useful protocol.

Thanks in advance.

Guy

Modifications of human and viral DNA by 
formaldehyde fixation
Laboratory investigation 1994 vol:71  No 4  
pp.604-611



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