Two new fluorescent dyes applicable for visualization of fungal cell walls.

Two fluorophores, Solophenyl Flavine 7GFE 500 and Pontamine Fast Scarlet 4B, not heretofore reported upon are described as useful dyes of fungal cell walls, septa and bud scars examined microscopically. The dyes, depending on the filter sets used, yield fluorescently stained material generally in the blue to green and yellow to red wavelengths for Solophenyl Flavine 7GFE 500 and Pontamine Fast Scarlet 4B, respectively. They provide an excellent alternative to the more commonly used fluorophore, Calcofluor White M2R. The two fluorophores, in addition to being used at various spectral wavelengths from mercury arc sources, can be used with laser sources providing 488 nm and 543 nm line wavelengths, common to most scanning confocal microscopes. Unlike Calcofluor, Solophenyl Flavine 7GFE 500 and Pontamine Fast Scarlet 4B do not fade quickly when exposed to selected light wavelengths; however, like Calcofluors they are compatible with living fungal cells.