Abstract: The invention describes the preparation and use of fluorescent stains for nucleic acids derived from unsymmetrical cyanine dyes comprising a substituted benzazolium ring system linked by a methine bridge to a pyridinium or quinolinium ring system having at least one substituent on the pyridinium or quinolinium ring that contains a heteroatom. The presence of the heteroatom-containing substituent results in higher sensitivity to oligonucleotides and larger nucleic acid polymers in a wide range of cells and gels, and for use in analysis of cell structure, membrane integrity or function.

Abstract: The invention relates to a method of analyzing a sample thought to contain bacteria using an aqueous solution comprising one or more fluorescent dyes: a fluorescent dye of formula I, a fluorescent dye of formula II, a fluorescent dye of formula III, and a fluorescent dye of formula IV. Each of the dyes differ each from the other in their affinity for nucleic acids and in their spectral response to different types of bacteria in the sample. The first three dyes are nucleic acid stains and the fourth dye is a fluorescent reagent that binds selectively to cell surface components. The fluorescent dyes of formula I are highly membrane-permeant cyanine dye derivatives and label all bacteria, whether live or dead, whether Gram positive or Gram negative. The dyes of formula II label only live Gram positive bacteria and label all dead bacteria, whether Gram positive or negative. The dyes of formula II bind to nucleic acids preferentially with respect to the dyes of formula I.

Abstract: The invention relates to a method of analyzing the viability of a sample of cells using an aqueous solution comprising two fluorescent dyes. Dye I has the formula: ##STR1## where R.sup.2 is C.sub.1-6 alkyl; Z.sup.- is a biologically compatible counterion;X is O; S; Se; or NR.sup.15, where R.sup.15 is H or C.sub.1-6 alkyl; or CR.sup.16 R.sup.17, where R.sup.16 and R.sup.17, which may be the same or different, are independently H or C.sub.1-6 alkyl, or the carbons of R.sup.16 and R.sup.17 taken in combination complete a five or six membered saturated ring; and the benzazolium is optionally further substituted;n=0, 1, or 2;Y is --CR.sup.3 .dbd.CR.sup.4 --; p and m=0 or 1, such that p+m=1;R.sup.5 is a C.sub.1-6 alkyl, C.sub.1-6 alkenyl, C.sub.1-6 polyalkenyl, C.sub.1-6 alkynyl or C.sub.1-6 polyalkynyl group; or R.sup.5 is an OMEGA;R.sup.3, R.sup.4, R.sup.6 and R.sup.7, which may be the same or different, are independently H; or a C.sub.1-6 alkyl, C.sub.1-6 alkenyl, C.sub.1-6 polyalkenyl, C.sub.1-6 alkynyl or C.

Abstract: The invention relates to a method of forming distinctive intravacuolar structures that are unique to fungal cells and can be correlated with cell viability. The preferred dyes of the present invention are described by the formula: ##STR1## wherein each R.sup.1 is independently H; or an alkyl group having from 1-6 carbons; or a trifluoromethyl; or a halogen; or --OR.sup.6, --SR.sup.6 or --(NR.sup.6 R.sup.7) where R.sup.6 and R.sup.7, which can be the same or different, are independently H; or alkyl groups having 1-6 carbons; or 1-2 alicyclic, heteroalicyclic, aromatic or heteroaromatic rings, containing 1-4 heteroatoms, wherein the heteroatoms are O, N or S; or R.sup.6 and R.sup.7 taken in combination are --(CH.sub.2).sub.2 --M--(CH.sub.2).sub.2 -- where M=a single bond, --O--, --CH.sub.2 --, or --NR.sup.8 -- where R.sup.8 is H or an alkyl having 1-6 carbons; and t=1-4;R.sup.2 is an alkyl group having 1-6 carbons;X is O, S, Se or NR.sup.9, where R.sup.9 is H or an alkyl group having 1-6 carbons; or X is CR.

Abstract: The invention describes the preparation and use of fluorescent stains for nucleic acids derived from unsymmetrical cyanine dyes. In particular, the invention describes unsymmetrical cyanine dyes having a saturated or unsaturated cyclic substituent. The dyes of the invention possess superior fluorescent characteristics when complexed with nucleic acids, and have utility in any application which requires detection of nucleic acids. The presence of the cyclic substituent results in improved permeability in a wide range of living cells, resulting in improved detection of intracellular nucleic acids.