Immunofluorescence

Immunofluorescence (IF) is a type of immunohistochemistry technique that utilizes fluorophores to visualize various cellular antigens such as proteins. This technique can be utilized to visualize the localization of various cellular components within cells, tissues as well as in 3D culture-derived cellular spherical structures. Fluorophore, compounds that emit light when exposed to a certain wavelength of light are essential for IF. To detect protein expression, the biological sample of interest is incubated with an antibody specific to the protein of interest; the antibody may be coupled to a fluorophore (direct fluorescence) or may be detected by a secondary antibody conjugated to a fluorophore (indirect fluorescence). The proteins or antigens can then be visualized by examination under a fluorescent microscope or a confocal microscope depending on the biological question being addressed by this method. This technique is commonly used in clinical practice as well as in research applications to optically determine protein expression and cellular and intracellular localization.