Hi Sbwa,
Yes, DNA can be isolated from tissue specimens in both paraffin and
plastic embedded tissue. It's certainly not the optimal way to obtain
DNA, but it is possible.
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2235515&dopt=Abstract
"The amount of tissue that should be included in a microdissection
target is dependent on the type of testing to be performed on the
tissue.26 Because PCR assays are highly sensitive, most PCR
applications will require a very small volume of DNA as the starting
template. Samples can potentially contain as few as 10 cells or can be
very cellular if there is a need for a large amount of DNA.27 However,
the reagents utilized should be scaled for the amount of raw DNA
included in the reaction mixture, and the amount used should be
consistent throughout an experiment."
"Fragments of DNA in paraffin-embedded tissues are still relatively
intact but are much shorter than those obtained from fresh or
snap-frozen tissue samples. Therefore, in designing PCR primers for
microdissected paraffin-embedded tissues, it is optimal to keep PCR
products small to optimize the amplification (ie, <200 base pairs).
PCR with longer targets may not be successful."
http://www.rednova.com/news/science/113300/microdissection_techniques_for_molecular_testing_in_surgical_pathology/
http://jmd.amjpathol.org/cgi/content/full/1/1/17
"To overcome this obstacle and permit both cellular morphology and
nucleic acid content to be preserved to the fullest extent, we
instituted a system of cold-temperature plastic resin embedding based
on the use of the water-miscible methyl methacrylate polymer known as
Immunobed (Polysciences, Warminster, PA)."
"The logical solution to this problem is a method for tissue fixation
and processing that maintains cellular integrity while quantitatively
and qualitatively preserving nucleic acids. Protocols designed to
protect nucleic acids are also likely to influence favorably the
availability of other cellular constituents including proteins,
carbohydrates, and lipids. In this report, we present such a system,
which is both easy and cost-effective to apply. The system is based on
an established process of cold-temperature embedding of tissue
specimens in an inert plastic resin with water-miscible
characteristics (Immunobed Kit, Polysciences, Warminster, PA). The
technique, termed the Immunobed method, has been used successfully for
ultrastructural immunocytochemistry. We report here that the system,
which allows tissue sections to be cut as thin as 0.5 µm, confers
excellent retention of long DNA and RNA lengths suitable for detailed
genetic analysis. Through the use of microdissection techniques, this
system permits the positive attributes of both microscopic and
molecular analysis to be realized for molecular pathology research
purposes as well as for clinical diagnosis and treatment."
http://jmd.amjpathol.org/cgi/content/full/1/1/17
Hope this is helpful! If not, please request an Answer Clarification,
before rating.
Sincerely, Crabcakes |
