A Cut above the Rest

Laser Microdissection is an intermediate step in the preparation of tissue specimens for research.  This service is provided by our tissue bank and gives researchers the ability to obtain macromolecules (DNA, RNA and protein) from specific cell types of a tissue specimen.  There are three Microdissection Microscopes currently in the market- Arcturus Pixcell, Leica Lasermicrodissection ASLMD and the Zeiss PALM.  We currently use the Leica ASLMD system.

Our primary focus in Windber is the study of breast tissue which is highly heterogeneous with numerous cell types within the primary tumor and the surrounding tissue.  Laser microdissection has allowed us to isolate pure samples from both invasive and in situ tumors (with and without involvement within invasive tumors), as well as the microenvironment surrounding the tumors that can then be used for downstream analyses.

We have used Laser Microdissected tissue samples for a variety of protocols requiring the preparation of homogenous isolates of DNA, RNA and protein.  Because the quality of RNA extracted from tissues can be affected by sample preparation and processing, we have fine-tuned our procedures for processing these samples.  Our protocols include careful cleaning of all equipment with RNAse inhibitors, use of special stains with lower water content, and rapidly performing the isolation process.  The time to process each sample is kept to less than 30 minutes from the time the specimen is sectioned through staining, microdissection and placement into the cell lysis buffer.  Below are images of a ductal carcinoma in situ (DCIS) from which RNA was isolated from the Microdissected cells.  The image labeled (A) is an Hematoxylin and Eosin Stain; (B) is a representative section in the same area stained with the RNA staining procedure and image (C) is the DCIS after Microdissection.

We have published details of our protocols in the chapter titled- “Laser Microdissection for Gene Expression Profiling” in the book “Laser Capture Microdissection Methods and Protocols Series: Methods in Molecular Biology”, Vol 755, Second Edition, Humana Press. 



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