HeLa Cell Histones with Fluorescein

YFP Bandpass Emission (Narrow Bandwidth Excitation) Blue-Green Set

Fluorescence emission intensity from a culture of HeLa cells that were immunofluorescently labeled with primary anti-histone (pan) mouse monoclonal antibodies followed by goat anti-mouse Fab fragments conjugated to fluorescein (FITC). In addition, the specimen was simultaneously stained for filamentous actin with the ultraviolet-absorbing probe Alexa Fluor 350 conjugated to phalloidin, and for the intracellular mitochondrial network with MitoTracker Red CMXRos. The visible light absorption maximum of fluorescein is 490 nanometers and the emission maximum occurs at 525 nanometers, values that fall within the useful range of the Nikon YFP HYQ filter combination. The primary antibody, produced from purified nuclear fractions of HeLa cells, binds specifically to an antigen determinant that is present on all five histone proteins (H1, H2A, H2B, H3, and H4). Note the strong green fluorescence emission exhibited by both the interphase nuclei and those in various stages of mitosis, while no signal is observed from the blue and red fluorophores (Alexa Fluor 350 and MitoTracker Red) targeting actin and mitochondria, respectively.