No Evidence for Interference of Hematoxylin and Eosin (HE) Staining in DNA Testing: Utility of DNA Extraction from HE-Stained Archival Tissue Sections

摘要

Although histochemical staining has been believed to inhibit DNA amplification reaction, no previous study has systematically evaluated the influence of histochemical staining on downstream molecular assays. To evaluate an influence of hematoxylin and eosin (HE) staining on DNA testing, we isolated DNA from 10 unstained, 10 hematoxylin-stained, 10 eosin-stained or 10 HE-stained tissue sections (ie, 4 groups), from each of 5 colon cancers. Among those 4 groups, we did not observe any significant or appreciable difference in DNA fragmentation by agarose gel electrophoresis; in DNA amplification by real-time PCR; in microsatellite PCR fragment analyses; or in PCR-Pyrosequencing. As a proof-of-principle study, we successfully performed microsatellite instability analysis and sequencing of KRAS and BRAF on over 1300 colorectal cancers using DNA extracted from HE stained tissue sections. Our data provide no evidence for interfering effect of HE staining on DNA testing, suggesting that DNA from HE-stained sections can be effectively used for routine DNA testing.