Laser capture microdissection

Laser microdissection is a microscopic method for laser-assisted microdissection of tissues and cells.

General

The technique was developed in the mid -1970s by scientists at the University of Bonn, Sandoz AG and the BTG Biotechnology GmbH in Munich. In certain cases, homogeneous cells can be obtained by laser capture microdissection, so that the sensitivity of subsequent downstream analyzes can be fully exploited. For the purpose of isolation and molecular analysis of morphologically and phenotypically different types of cells, the system was first commercially developed and marketed by Arcturus later. Selective choice of cell types can be carried out due to specific morphological criteria by histological staining of tissue sections. As can be the selection of a tissue immunohistochemical reaction due to antigen expression or genotypic identification by in situ hybridization. Other techniques for the isolation of cell populations such as FACS ( fluorescent - activated cell sorting ) or magnetic bead - based cell separation based on indirect techniques without light microscopic visualization. A big advantage of LCM is the selection of cells under direct light microscopic control.

Areas of application

The system was originally used mainly in molecular pathology for the isolation and analysis of cancer cells, but is becoming increasingly popular in other areas of bioanalysis.

Systems

Generally, there are two systems of laser-assisted microdissection: laser microbeam microdissection and laser capture microdissection:

Laser microbeam microdissection

At the laser microbeam microdissection can be cut from a tissue section using an infrared or ultraviolet laser, a single cell or a desired region. Pure sample was then either falls under the influence of gravity into a reaction vessel (Leica system) is (PALM system) or indirectly, lifted against the force of gravity in such a propelled together with the sample covering membrane of the adhesiven lid of the reaction vessel ( MMI system ).

Laser Capture Microdissection

The technique was developed in the mid 1990s at the National Institutes of Health by Michael R. Emmert - Buck et al. In laser capture microdissection (LCM ) a thermoplastic membrane, which may be connected to a reaction vessel, melted by an infrared or ultraviolet laser. The inert membrane fuses with the fabric cut and can be removed in the subsequent step. This enables the production of specific cell populations.

Both methods through the short contact of the tissue with the laser beam of only 1 nanosecond, this does not change and hence remains intact.