๐ ็ธฝ็ฎ้ ๏ฝ ๐ ่ฑๆๅๆ๏ผๆฌ็ฏ๏ผ ๏ฝ ๐ ๅฎๆด็ฟป่ญฏ ๏ฝ โญ ็ฒพ่ฏ็ญ่จ
Immunofluorescence
Immunofluorescence
Immunofluorescent techniques have the potential to define antigen-antibody interactions at a subcellular level.1 This interaction requires the irreversible binding of a readily identifiable label for its recognition.1,2 Fluorochromes such as rhodamine or fluorescein are labels that can absorb radiation in the form of ultraviolet or visible light.1โ5 Direct and indirect immunofluorescence (IMF) techniques demonstrate a range of tissue antigens of
dermatopathological importance, including the diagnosis of infectious and autoimmune blistering disorders.3 In the direct IMF technique, antibody is conjugated directly with a fluorochrome and is used to detect an antigen in a tissue section using ultraviolet light microscopy.1โ3 In the indirect IMF technique, patient serum (containing the antibodies) interacts with a tissue section containing the antigen. Antibody to a human immunoglobulin, conjugated to a fluorochrome, is applied thereafter.1โ7 The successful demonstration of the antigen requires the antigen to remain sufficiently insoluble in situ. Skin biopsies for direct immunofluorescence can be transported fresh on saline-soaked gauze in a container on ice, or in a transport medium such as Michel medium.8 The transport medium must be maintained at a pH of 7.0โ7.2.1,3,5 The main uses for IMF in dermatopathology are in the interpretation of the autoimmune blistering diseases, lupus erythematosus, and vasculitis.6,7 In general, immunofluorescence has the following advantages over immunohistochemistry:
โข more sensitive detection of antigen.
โข use of special fixation that preserves โdifficultโ antigens. Fading of immunofluorescence sections can be overcome by the use of anti-fading mountants.
41 Frozen section examination of skin specimens