A simple, precise and economical microdissection technique for analysis of genomic DNA from archival tissue sections.

Formalin-fixed and paraffin-embedded tissues are valuable resources for retrospective analysis of the molecular changes in DNA present in tumour tissues. One common problem that precludes an accurate DNA analysis in a human tissue sample is cellular heterogeneity. We have developed a simple and inexpensive, but micrometrically precise, microdissection technique that allows for selective isolation of minute cell clusters and even single cells from archival tissue sections. The features of our technique include use of a 30G1/2 needle affixed to a mechanical micromanipulator as a dissector sharp enough to be used for dissection of even single cells and use of the stage and focus control knobs of the microscope to scrape the target cells instead of moving the needle during microdissection. The main advantages of this technique over the current methods lie in its simplicity, low cost, easy handling and precision.