A compound of Formula la or 1b: wherein: X is O, S, or -C(CH 3) 2 -; A is -OR 1 or NR 1 R 1a; B is =O or =N + R 4 R 4a; C is -OR 4 or -NR 4 R 4a; R 1, R 1a, R 4, and R 4a are each independently H or alkyl, unsubstituted or substituted with-L-SO 3 -, -L-PO 3 2-, a water-soluble polymer, or with -L-R x; or one or more pair of R 1 and R 1a or R 4 and R 4a together with the nitrogen to which they are attached form a saturated or unsaturated ring optionally substituted by any of -L-SO 3 -, -L-PO 3 2- and -L-R x; R 7 is a 5-10 membered monocyclic or bicyclic heteroaryl group, unsubstituted or substituted with halogen, CO 2 -, CN, alkyl, alkenyl, alkoxy, alkylthio, alkylamino, dialkylamino, alkylaminocarbonyl, dialkylaminocarbonyl, alkylaminosulfonyl, dialkylaminosulfonyl, aminosulfonyl, aryl, heteroaryl, -L-PO 3 2-, L-SO 3 -, or -L-R x; R' 7 is H, OH, CN, or C 1 -C 6 alkoxy; or R' 7 in combination with the monocyclic or bicyclic heteroaryl group of R 7 forms a 5- or 6- membered spirolactone or spirosultone ring; R 2, R 3, R 5, R 6, R 8, R 9, are each independently H, halogen, CN, alkyl, alkenyl, alkoxy, aryl, heteroaryl, -L-PO 3 2-, -L-SO 3 -, or -L-R x; or one or more pair of R 2 and R 1a, R 3 and R 4a, R 4 and R 5, R 5 and R 6, R 8 and R 9, or R 9 and R 1, together with the atoms to which they are attached form one or more fused saturated or unsaturated rings that are optionally substituted by at least one halogen, CN, alkyl, alkenyl, alkoxy, alkylthio, alkylamino, dialkylamino, alkylaminocarbonyl, dialkylaminocarbonyl, alkylaminosulfonyl, dialkylaminosulfonyl, aminosulfonyl, aryl, heteroaryl, -L-PO 3 2-, L-SO 3 -, or -L-R x; R x is a reactive group selected from a group consisting of an activated ester, an acrylamide, an acyl azide, an acyl halide, an acyl nitrile, an aldehyde, a ketone, an alkyl halide, an alkyl sulfonate, an anhydride, an aryl halide, an aziridine, a boronate, an epoxide, a haloacetamide, a halotriazine, an imido ester, an isocyanate, an isothiocyanate, a maleimide, a phosphoramidite, a silyl halide, a sulfonate ester, a sulfonyl halide, an azide, cis-platinum, an amine, an aniline, a thiol, an alcohol, a phenol, a hydrazine, a hydroxylamine, a carboxylic acid, a glycol, or a guanosine; L is a bond or n; each Q is independently NR d, S t, O, C(=X), (C=X), substituted or unsubstituted alkyl, substituted or unsubstituted heteroalkyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted cycloalkyl, or substituted or unsubstituted heterocycloalkyl, wherein t is 0-2, and no more than two NR d are adjacent and no two O are adjacent; n is 1-20; each R d is H, substituted or unsubstituted alkyl; and at least one of R 2, R 3, R 5, R 6, R 8, or R 9 is -L-SO 3 -, X is O, S, or -C(CH 3) 2 -; A is -OR 1 or NR 1 R 1a; B is =O or =N + R 4 R 4a; C is -OR 4 or -NR 4 R 4a; R 1, R 1a, R 4, and R 4a are each independently H or alkyl, unsubstituted or substituted with-L-SO 3 -, -L-PO 3 2-, a water-soluble polymer, or with -L-R x; or one or more pair of R 1 and R 1a or R 4 and R 4a together with the nitrogen to which they are attached form a saturated or unsaturated ring optionally substituted by any of -L-SO 3 -, -L-PO 3 2- and -L-R x; R 7 is a 5-10 membered monocyclic or bicyclic heteroaryl group, unsubstituted or substituted with halogen, CO 2 -, CN, alkyl, alkenyl, alkoxy, alkylthio, alkylamino, dialkylamino, alkylaminocarbonyl, dialkylaminocarbonyl, alkylaminosulfonyl, dialkylaminosulfonyl, aminosulfonyl, aryl, heteroaryl, -L-PO 3 2-, L-SO 3 -, or -L-R x; R' 7 is H, OH, CN, or C 1 -C 6 alkoxy; or R' 7 in combination with the monocyclic or bicyclic heteroaryl group of R 7 forms a 5- or 6- membered spirolactone or spirosultone ring; R 2, R 3, R 5, R 6, R 8, R 9, are each independently H, halogen, CN, alkyl, alkenyl, alkoxy, aryl, heteroaryl, -L-PO 3 2-, -L-SO 3 -, or -L-R x; or one or more pair of R 2 and R 1a, R 3 and R 4a, R 4 and R 5, R 5 and R 6, R 8 and R 9, or R 9 and R 1, together with the atoms to which they are attached form one or more fused saturated or unsaturated rings that are optionally substituted by at least one halogen, CN, alkyl, alkenyl, alkoxy, alkylthio, alkylamino, dialkylamino, alkylaminocarbonyl, dialkylaminocarbonyl, alkylaminosulfonyl, dialkylaminosulfonyl, aminosulfonyl, aryl, heteroaryl, -L-PO 3 2-, L-SO 3 -, or -L-R x; R x is a reactive group selected from a group consisting of an activated ester, an acrylamide, an acyl azide, an acyl halide, an acyl nitrile, an aldehyde, a ketone, an alkyl halide, an alkyl sulfonate, an anhydride, an aryl halide, an aziridine, a boronate, an epoxide, a haloacetamide, a halotriazine, an imido ester, an isocyanate, an isothiocyanate, a maleimide, a phosphoramidite, a silyl halide, a sulfonate ester, a sulfonyl halide, an azide, cis-platinum, an amine, an aniline, a thiol, an alcohol, a phenol, a hydrazine, a hydroxylamine, a carboxylic acid, a glycol, or a guanosine; L is a bond or n; each Q is independently NR d, S t, O, C(=X), (C=X), substituted or unsubstituted alkyl, substituted or unsubstituted heteroalkyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted cycloalkyl, or substituted or unsubstituted heterocycloalkyl, wherein t is 0-2, and no more than two NR d are adjacent and no two O are adjacent; n is 1-20; each R d is H, substituted or unsubstituted alkyl; and