Quantitative amplification of genomic DNA from histological tissue sections after staining with nuclear dyes and laser capture microdissection

Laser capture microdissection (LCM) allows the selective sampling of tissue from histological sections. A prerequisite for this technique is the avail ability of histological dyes that do not interfere with downstream analysis of the sampled genetic material. We have examined the effect of four histo logical nuclear dyes (methyl green, hematoxylin, toluidine blue O, azure B) on TaqMan polymerase chain reaction amplification of beta -actin. genomic DNA prepared from fixed and frozen tissue. Tissue sampled from the histolog ical sections by manual dissection was compared with tissue sampled by LCM. As previously reported, when manually dissected tissue sections were analy zed, polymerase chain reaction amplification of DNA after hematoxylin stain ing was inferior to that after staining with the other dyes. In contrast, w hen tissue sampled by LCM was examined, DNA recovery after hematoxylin stai ning was equivalent to the recovery after methyl green staining. We conclud e that DNA recovery from LCM-sampled tissue is independent of the histologi cal stain chosen to highlight nuclear detail.