immunofluorescence /im·mu·no·flu·o·res·cence/ (-fldbobr-res´ens) a method of determining the location of antigen (or antibody) in a tissue section or smear by the pattern of fluorescence resulting when the specimen is exposed to the specific antibody (or antigen) labeled with a fluorochrome.
immunofluorescence
immunofluorescence [im″u-no-floo″o-res´ens]
im·mu·no·fluo·res·cence ( m y -n -fl -r s ns, -flô-, -my -)n. Any of various methods that use antibodies chemically linked to a fluorescent dye to identify or quantify antigens in a tissue sample. |
immunofluorescence
[-floo͡res′əns]
Etymology: L, immunis + fluere, to flow
a technique used for the rapid identification of an antigen by exposing it to known antibodies tagged with the fluorescent dye fluorescein and observing the characteristic antigen-antibody reaction of precipitation. As the fluorescent antibody reacts with its specific antigen, the precipitate appears luminous in the ultraviolet light projected by a fluorescent microscope. Many of the most common infectious organisms can be identified by this technique. Among them are Candida albicans, Haemophilus influenzae, Neisseria gonorrhoeae, Shigella, Staphylococcus aureus, and several viruses, including rabies virus and many enteroviruses. See also fluorescent antibody test, fluorescent microscopy. immunofluorescent, adj.
immunofluorescence [im″u-no-floo″o-res´ens]
a method of determining the location of antigen (or antibody) in a tissue section or smear using a specific antibody (or antigen) labeled with a fluorochrome. There are two major types of immunofluorescence techniques, both based on the antigen--antibody reaction, in which the antibody attaches itself to a specific antigen.
In the direct fluorescent antibody (DFA) method, the antibody coats the antigen, for example, a bacterial cell, and cannot be easily removed by elution (washing). The antibody remains attached to the cell after all nonantibody globulin has been washed away. Since the antibody has been rendered fluorescent by conjugation with fluorescein or another dye, the outline of the bacterial cell that it coats can readily be seen with a special microscope.
In the indirect fluorescent antibody (IFA) method, the specific antibody is allowed to react with the antigen. The nonantibody globulin is then washed off. This is then treated with a labeled antibody to the specific antibody. For example, if the specific antibody was raised in a rabbit, it is then treated with fluorescein-labeled anti-rabbit globulin, which results in a combination of this labeled antibody with the rabbit immunoglobulin already attached to the antigen.
Fluorescent antibody studies have been used in the detection of numerous bacterial, viral, fungal, and protozoan infections and in the identification of many microscopic tissue constituents.
In the direct fluorescent antibody (DFA) method, the antibody coats the antigen, for example, a bacterial cell, and cannot be easily removed by elution (washing). The antibody remains attached to the cell after all nonantibody globulin has been washed away. Since the antibody has been rendered fluorescent by conjugation with fluorescein or another dye, the outline of the bacterial cell that it coats can readily be seen with a special microscope.
In the indirect fluorescent antibody (IFA) method, the specific antibody is allowed to react with the antigen. The nonantibody globulin is then washed off. This is then treated with a labeled antibody to the specific antibody. For example, if the specific antibody was raised in a rabbit, it is then treated with fluorescein-labeled anti-rabbit globulin, which results in a combination of this labeled antibody with the rabbit immunoglobulin already attached to the antigen.
Fluorescent antibody studies have been used in the detection of numerous bacterial, viral, fungal, and protozoan infections and in the identification of many microscopic tissue constituents.
Direct immunofluorescence. In direct immunofluorescence the object is visualized using a fluorescein-tagged antibody. From Hart and Shears, 1997.
immunofluorescence
a method of determining the location of antigen (or antibody) in a tissue section or smear using a specific antibody (or antigen) labeled with a fluorochrome. In the direct methods, the fluorochome is chemically linked to the specific antibody. In indirect methods, a labeled anti-immunoglobulin that binds to the specific antibody is used. See also fluorescence microscopy.
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