MICRODISSECTION OF STAINED ARCHIVAL TISSUE

In many tissues the preinvasive stage of neoplastic progression can be identified histologically as dysplasia or in situ disease. There is m uch interest in defining the molecular events associated with the earl y stages of neoplasia. Retrieval of histologically recognisable preinv asive neoplastic tissue uncontaminated by inflammatory or stromal cell s is important for genetic studies using polymerase chain reaction (PC R) assay. A novel method for microdissection is described in which 10 mu m sections are dewaxed, stained with haematoxylin and eosin, dried, covered with Sellotape, and the tissue cut out using a scalpel blade under direct visual control. The method is quick, eliminates problems of operator tremor, preserves the architecture of the microdissected t issue (for photographic documentation) and requires no special equipme nt. The presence of Sellotape and adhesive in the reaction mixture has no detrimental effect on the ability to extract DNA or to perform PCR .