Laser+Scanning+Cytometry+(LSC)

Laser scanning cytometry (LSC) is a hybrid of flow cytometry (FC) and image cytometry (IC). This particular technique utilizes a microscope and requires the specimen of interest to be placed on a slide, which is then scanned rapidly by a laser beam, which in turn excites the specimen. The light scattered by the specimen is recorded and then imaged. The fluorescent light emitted by the specimen is picked up through a computer-controlled camera in addition to a scanning mirror. The information then travels to one of four photomultipliers, which record specific wavelengths of light. The information can be visualized either through the computer-controlled camera or an eyepiece utilizing a light source separate from the laser.

LSC offers many advantages to the previous method of FC with few of the limitations associated with FC. In contrast to imaging done using flow cytometry, laser-scanning cytometry requires that cell analysis be done on a slide, which ultimately allows access to morphological characteristics for evaluation and measurement. Also, due to the requirement of a slide specimens may be later reevaluated using different contour and threshold settings.

Laser scanning cytometry has a variety of applications and can be useful for imaging any of the following: ú Immunophenotyping ú Cell cycle analysis ú Detection of apoptosis ú Analysis of enzyme kinetics, drug uptake, or ligand binding ú Analysis of activation or deactivation of macromolecules by their translocations ú FISH analysis ú Correlation of cell function with morphology and other cell attributes ú Cell-to-cell interactions ú Pathology and tissue section analysis

Darzynkiewicz et. al. (2011) highlights the ability of laser scanning cytometry to be utilized for viewing micronucleus (MN) of cells currently growing //in vitro// allowing for a better understanding of the development of MNs. LSC has also been used to view buccal (cheek) MN which are noted for the visible presence of a central nucleus in addition to at least one or more smaller MN.

Takahaski et. al. used laser scanning cytometry in conjunction with amplified immunoflourescent staining to develop quantitative methods of immunoprofiling regulatory T cells. This will eventually be beneficially applicable to biopsy samples from transplanted organs.

Laser scanning cytometry techniques have been utilized by Lee et. al. to image and evaluate circulating tumor cells on a large-scale, single-cell level. This particular application may eventually lead to the isolation and identification of the tumor cells that initiate metastisis.

References: Alberts, B., Johnson, A., Lewis, J., Raff, M., Roberts, K., and Walter, P. (2008) Molecular Biology of the Cell, 4th or 5th ed., Garland Science Publishing Company; ISBN: 0-8153-4105-9

Darzynkiewicz, Z., Bedner, E., Li, X., Gorczya, W., and Melamed, M.R. (1999) Laser-scanning cytometry: a new instrumentation with many applications. //Experimental Cell Research// 249: 1-12

Darzynkiewicz, Z., Smoleweki, P., Holden, E., Luther, E., Henriksen, M., Francois, M., Laifert, W., and Fenech, M, (2010) Laser scanning cytometry for automation f microneucleus assay. //Mutagenesis// 26 (1): 153-161.

Lee, S., Kim, G., Wu, Y., Kim, D., Lu, Y., Kwak, M., Han, L., Hyung, J., Seol, J., Sander, C., Gonzalez, A., Li, J., and Fan, R. (2012) Nanowire substrate-based laser scanning cytometry for quantitation of circulation tumor cells. //American Chemical Society// 12: 2697-2704.

Takahashi, H., Ruiz, P., Miki, A., Mita, S., Barker, A., Tzakis, A., and Ichii, H. (2009) In situ quantitative immunoprofiling of regulatory t calls using laser scanning cytometry. //Transplantation Proceedings// 41: 238-239