Quaternary benzo[c]phenanthridine alkaloids (QBAs) are natural products isolated from plants of Fumariaceae, Papaveraceae, Ranunculaceae and Rutaceae families. They are intensively studied for their biological activities. Nevertheless they have also attractive fluorescence properties. Chromophores responsible for fluorescence are fused aromatic rings with electron-donor groups containing oxygen (OH; OCH3; OCH2O). Recently we have described fluorescent characteristics of QBAs - macarpine (MA), sanguirubine (SR), chelirubine (CHR), sanguilutine (SL), chelilutine (CHL), sanguinarine (SA) and chelerythrine (CHE) upon interacting with living cells. All these alkaloids immediately enter living cells and MA, CHR and SA bound DNA and showed nuclear architecture similar as common DNA dyes. Moreover, MA binds DNA stoichiometrically and can rapidly report the cellular DNA content in living cells at a resolution level adequate for cell cycle analysis. QBAs were excitable by common argon lasers (488 nm) emitting at the range 575 - 755 nm (i.e. fluorescence detectors FL2-5). Spectral characteristics of MA allow simultaneous surface immunophenotyping. These characteristics allow multiple applications of the above-mentioned QBAs with significant diagnostic utility. They can be used as supravital fluorescent DNA probes both in fluorescence microscopy and flow cytometry including multiparameter analysis.