Tissue-preserving approach to extracting DNA from paraffin-embedded specimens using tissue microarray technology.
BACKGROUND
DNA extracted from tumor cells or normal cells contained in formalin-fixed, paraffin-embedded tissues is widely used in many laboratories. The 2 most common procedures to isolate cells for DNA extraction from paraffin-embedded tissues are scalpel microdissection and laser capture microdissection. A new tissue- and time-conserving method for rapid DNA isolation from small cores taken from paraffin-embedded tissue blocks is described in this report.


METHODS
DNA was extracted from small tissue cores collected from paraffin-embedded tissue blocks at the time of tissue microarray construction. The quality and quantity of the DNA extracted was compared to DNA collected by scalpel microdissection. DNA collected from tissue cores was used in polymerase chain reaction (PCR) and loss of heterozygosity (LOH) analysis.


RESULTS
The quality and quantity of DNA obtained using tissue cores was comparable to DNA obtained by traditional methods. The tissue core method of DNA extraction preserves the tissue blocks from which the cores are extracted for future use. Adequate quantities of DNA can be successfully extracted from small segments of tissue cores and used for PCR. DNA isolated by tissue microdissection and the tissue core method were comparable when used to assess allelic heterozygosity on chromosome arm 18q.


CONCLUSIONS
The tissue core method of DNA isolation is reliable, tissue conserving, and time effective. Tissue cores for DNA extraction can be harvested at the same time as tissue microarray construction. The technique has the advantage of preserving the original tissue blocks for additional study as only tiny cores are removed.
Prince
Mark E
ME
Department of Otolaryngology-HNS, University of Michigan, 1500 E. Medical Center Drive, Ann Arbor, MI 48109, USA.
Ubell
Mathew L
ML
Castro
Jason
J
Ogawa
Haruko
H
Ogawa
Tetsuya
T
Narayan
Ajita
A
Paulino
Augusto
A
Cole
Andrew
A
Wolf
Gregory T
GT
Rubin
Mark A
MA
Lyons
Robert H
RH
Bradford
Carol R
CR
Carey
Thomas E
TE
D002294:Carcinoma, Squamous Cell / Q000235:genetics / Q000473:pathology; D002887:Chromosomes, Human, Pair 18; D004273:DNA, Neoplasm / Q000302:isolation & purification*; D006801:Humans; D007822:Laryngeal Neoplasms / Q000235:genetics / Q000473:pathology; D019656:Loss of Heterozygosity; D042282:Microdissection; D016612:Paraffin Embedding; D016133:Polymerase Chain Reaction; D046888:Tissue Array Analysis
D004273:DNA, Neoplasm