Laser+Microdissection

__**Laser Capture Microdissection **__ Bianca Camillaci
 * Basic Description: **

Laser Capture Microdissection (LCM) is a cutting edge technique that is used in cell biology. This technique utilizes a laser that is coupled into a microscope, and the microscope focuses on the tissue that is present on the slide. The user running the technique then defines the trajectory of the laser and the laser cuts that specific area of the tissue. This area is cut out and separated by the laser. After the tissue is cut there are several different techniques used to extract the tissue if it needs to be extracted. One such extraction includes pressing a sticky surface on the tissue, and then extracting the cut tissue. There is room for error with this because some of the tissue may stay stuck to the adhesive.




 * Purpose of Technique: **

 The purpose of this technique is to cut out small sections of tissue for further analysis without all the extra tissue around the area of interest. This can provide the researcher with specific data on a cell population without having to look at the unwanted cells. It allows for the isolation of a population of cells for further analysis (Espina).


 * Origin and History: **

The technique of Laser-capture microdissection has been progressively developing throughout the past 20 years. One of the first pattens being in 1996 with the development of the computerized microscope specimen encoder, another big one came in 2004 with the automated laser capture microdissection and more recently, in 2014 there has been pattens for Laser microdissection apparatus and methods as well as an automated microdissection instrument


 * Recent Research: **

One research article used the Laser Microdissection microscopy to cut the midsection of several different mosquito groups. The aim of the experiment was to determine a protocol that could inactivate pathogenic viruses by fixation, while at the same time preserving RNA from the mosquitos. The fact that Carneys method was effective in inactivating the virus will successfully preserving the RNA (Young).

Laser microdissection has also been applied in breast cancer proteomics. In order to extract just the tissue of interest, namely tumor cells and not other parts of the heterogeneous tissue such as blood vessels, immune cells, epithelial ducts etc., laser capture microdissection is used. This allows for relatively pure samples of the tumor cells when performing biomarker discovery type of studies (Rene)

Another study has used LCM in in neuronal type specific gene expression profiling. LCM is used to cut out specific molecular cascades associated with various neurological and psychological diseases. This cell-specific based analysis enables molecular fingerprinting, such as mRNA expression profiling, with out the disrupting effects of surrounding cells/ tissue structures. This technique is used on postmortem tissue but only can be done for about 2-3 days (Charmain)

Also in a recent study of EGFR and KRAS mutation analysis in cytologic samples of lung adenocarcinoma, LCM was used. LCM was used in order to isolate tumor cells to assess for EGFR and KRAS mutation from patients who were known to have adenocarcinomas. It is a very successful technique which allowed them to consistently detect the mutation from only 50 microdissected tumor cells. The consistency lead to an increase sensitivity of mutation detection and has been deemed as being able to significantly increase the number of lung adenocarcinoma patients that can be screened for EGFR and KRAS mutation (Chowdhuri)

Charmain Y Pietersen, Maribel P. Lim, Laurel Macey, Tsung-Ung W. Woo, and Cai C Sonntag, Neronal Type-Specific Gene Expression Profiling and Laser-Capture Microdissection. Methods in Molecular Biology. 22 June 2011. Volume 11. Pg 327-343
 * References: **

Chowdhuri, Xi, Pham, Hanson, Rodriguez-Canales, Berman, Rajan, Giaccone, Emmert-Buck, Raffeld, Filie, EGFR and KRAS mutation analysis in cytologic samples of lung adenocarcinoma enabled by laser capture microdissection. Modern Pathology. 2012. volume 25. Page 548-555

Espina, V. Laser-capture microdissection. Nature Protocols. 27 June 2006. Volume 1. Pg. 586-603

<span style="font-family: 'Times New Roman',Times,serif; font-size: 18px;">Rene B.H. Braakman, Theo M. Luider, John W.M Martens, John A Foekens, Arzu Umar, Laser Capture Microdissection Applications in Breast Cancer Proteomics. Methods in Microbiology. 22 June 2011. Volume 755. Pg 143-154

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<span style="font-family: 'Times New Roman',Times,serif; font-size: 140%;">Young, S. H. High Quality RNA Isolation from Aedes Aegypti Midguts using Laser microdissection microscopy. Parasites and Vectors. 19 May 2011. Volume 4. Pg. 4-83.