Coumarin AMCA

Aminomethylcoumarin Acetate (AMCA) conjugates absorb light maximally around 350 nm and fluoresce maximally around 450 nm. For fluorescence microscopy, AMCA can be excited with a mercury lamp and observed using a UV filter set. Since blue fluorescence is not well detected by the human eye, AMCA-conjugated secondary antibodies should be used only with the most abundant antigens in multiple-labeling experiments. Ways of improving the visibility of AMCA include dark adapting the eyes, using fluorite instead of glass objectives, avoiding mounting media that absorb UV light (such as plastic-based media), and capturing photographic images with blue-sensitive film or CCD cameras. AMCA fades rapidly in conventional epifluorescence and confocal microscopy, and therefore it should be used with mounting media containing an anti-fading agent such as n-propyl gallate.