New reagent for quenching lipofuscin autofluorescence in tissue sections for immunofluorescence staining.
Lipofuscin consists of highly autofluorescent granules of oxidized proteins and lipids that build up in the lysosomes of aging cells. Lipofuscin granules fluoresce brightly in all channels used for fluorescence microscopy, and accumulate in a variety of cell and tissue types with age. Consequently, imaging of specific immunofluorescence signal in certain adult human tissues or aged animal tissues can be virtually impossible unless methods are employed to quench or mask lipofuscin fluorescence.
Traditionally, Sudan Black B has been used to quench lipofuscin autofluorescence by incubating tissue sections with the dye after immunofluorescence staining. However, while it masks the autofluorescence from lipofuscin, Sudan Black B also introduces uniform non-specific background fluorescence in the red and far-red channels, limiting the use of fluorescent dyes in those wavelengths. Now Biotium has developed TrueBlack as a superior alternative to Sudan Black B. TrueBlack quenches lipofuscin fluorescence with far less increase in red/far-red background fluorescence. TrueBlack treatment can be performed before or after immunostaining. It is rapid, simple, and has minimal effect on signal from fluorescent antibodies or nuclear counterstains, thus preserving the signal-to-noise ratio of the immunostaining.
TrueBlack effectively eliminates lipofuscin autofluorescence in tissues like human brain and human retina. TrueBlack also can reduce autofluorescence from other sources, such as collagen, elastin, red blood cells, and general background fluorescence. It is not as effective at quenching these sources of autofluorescence as it is for lipofuscin, but it can improve background in human and non-human tissue types.