The intermediate filament protein vimentin is expressed by a number of different types of mesenchymal cells and in the precursor cells of astrocytes and neurons, while the closely related glial fibrillary acidic protein (GFAP) is specifically expressed in various astroglial cells and neural stem cells. These two proteins were visualized in a coronal rat brain section featuring the hypothalamus with mouse anti-vimentin and rabbit anti-GFAP primary antibodies detected with goat anti-mouse and anti-rabbit secondaries conjugated to Alexa Fluor probes (488 and 568, respectively). Nuclear DNA was subsequently labeled with the red-absorbing counterstain DRAQ5 (pseudocolored cyan). Images were recorded with a 40x oil immersion objective using a zoom factor of 1.2 and sequential scanning with the 488-nanometer spectral line of an argon-ion laser, the 543-nanometer line from a green helium-neon laser, and the 633-nanometer line of a red helium-neon laser. During the processing stage, individual image channels were pseudocolored with RGB values corresponding to each of the fluorophore emission spectral profiles unless otherwise noted above. View a larger version of this digital image. |