Immunofluorescence

From Wikipedia, the free encyclopedia

Immunofluorescence is the labeling of antibodies or antigens with fluorescent dyes. This technique is sometimes used to make viral plaques more readily visible to the human eye. Immunofluorescent labelled tissue sections are studied using a fluorescence microscope or by confocal microscopy.

Most commonly, immunofluorescence employs two sets of antibodies: a primary antibody is used against the antigen of interest; a subsequent, secondary, dye-coupled antibody is introduced that recognizes the primary antibody. In this fashion the researcher may create several primary antibodies that recognize various antigens, but, because they all share a common constant region, may be recognized by a single dye-coupled antibody. Typically this is done by using antibodies made in different species. For example, a researcher might create antibodies in a goat that recognize several antigens, and then employ dye-coupled rabbit antibodies that recognize the goat antibody constant region (denoted rabbit anti-goat). This allows re-use of the difficult-to-make dye-coupled antibodies in multiple experiments.

As with most fluorescence techniques, a significant problem with immunofluorescence is photobleaching.

Many uses of immunofluorescence have been outmoded by the development of recombinant proteins containing fluorescent protein domains, e.g. green fluorescent protein (GFP). Use of such "tagged" proteins allows much better localization and less disruption of protein function.