Investigation of Galectins in Frozen Tissue and Mammalian Cell Culture Using Confocal Miccroscopy

Galectins are multifunctional glycan-binding proteins present in various tissues that participate in multiple physiological and pathological processes and are considered as not only biomarkers of human diseases but also molecular targets for treating cancer and inflammatory illnesses in many organs. In the glycobiology field, it is crucial to determine the pattern of galectin expression and location in cells and tissues. Confocal microscopy is a powerful imaging technology that represents a unique approach to investigate the expression and location of biomolecules in various tissues and cells. The confocal microscope acquires images of the specimen through the reflected or fluorescent light from the objective's focal plane, using laser light focused on a small spot inside the tissue or cell. This technique provides high-resolution and high-contrast images without artifacts generated by conventional microscopy and enables reconstruction of virtual tridimensional images by acquiring multiple sections from several focal planes, which makes it possible to obtain the precise spatial location of any cellular structure or molecule. Furthermore, confocal microscopy is a non-invasive tissue imaging strategy used in clinical practices. We describe herein the immunofluorescence confocal method for examining galectins in frozen tissue sections and mammalian cell culture.