Cost-Effective and Practical Manual Microdissection Method for Accurate High-Purity Tissue Sampling

Tissue-based molecular analyses have become a mainstay of biomedical research, including high-throughput DNA and RNA sequencing, and for appropriate results, microdissection is necessary to enrich the target cells. Many types of microdissection methods have been developed, among which laser capture microdissection (LCM) is the most precise. However, LCM is expensive and requires specialized equipment and membrane slides. Herein, we present a modified manual microdissection method that is simple, inexpensive, and does not require special equipment. On a wet condition after microtome sectioning of non-stained formalin-fixed paraffin-embedded tissue, dissection of targeted foci of as small as 0.02 square millimeters was possible using a needle under stereomicroscopic observation. Three representative cases with 16 foci were demonstrated, with successful detection of KRAS and/or GNAS mutations by direct sequencing and Cycleave polymerase chain reaction (PCR) assays. This modified manual microdissection method is simple and efficient, allowing us to obtain materials with a high tumor purity in any laboratory.