Carbazolylvinyl dye protein stains

A composition of matter, comprising:

• a) a compound of the formula
• Q—B—Z
• where Q is a nitrogen heterocycle of the formula
• wherein
• R1 and R2 are optionally and independently H, Cl, F, sulfo, carboxy, salt of sulfo, salt of carboxy, C1-C6 alkyl or C1-C6 alkoxy;
• or R1 and R2 taken in combination form a fused 6-membered aromatic ring that is itself optionally further substituted one or more times by H, Cl, F, C1-C6 alkyl or C1-C6 alkoxy, carboxy, sulfo or salts of carboxy or sulfo;
• R3, R4, R5, and R6 are optionally and independently H, Cl, F, C1-C6 alkyl or C1-C6 alkoxy;
• or any two adjacent substituents of R3, R4, R5 and R6, when taken in combination, form a fused 6-membered aromatic ring that is optionally and independently substituted one or more times by H, Cl, F, C1-C6 alkyl, C1-C6 alkoxy, carboxy, sulfo or salts of carboxy or sulfo;
• X is —S—, —O—, —NR7—, or —CR7R8—, wherein R7 and R8 are optionally and independently H, Cl, F, phenyl, or C1-C6 alkyl;
• or R7 and R8 taken in combination complete a 5- or 6-membered saturated ring;
• TAIL is a quaternizing moiety that is attached to the nitrogen atom of Q through a carbon atom and is either —(CH2)mSO3— or —(CH2)mCO2—, where the subscript m=1 to 6 and the negative charge is balanced by a positive charge on the nitrogen heterocycle Q;
• or TAIL is —(CH2)mNRaRb or —(CH2)mN+RaRbRc, where Ra, Rb and Rc, which may be the same or different, are H or C1-C6 alkyl, or Ra and Rb taken in combination form a 3-6 membered ring that optionally incorporates a heteroatom that is O, NRd or S, where Rd is H or C1-C6 alkyl;
• and wherein any net positive charges on the dye are balanced by organic or inorganic anions;
• B is a covalent bridge having the formula —(CH═CH)n— where n=1, 2 or 3;
• and Z is carbazolyl moiety of the formula
• where
• R11 is C1-C6 alkyl or is phenyl, or is phenyl substituted one or more times by H, Cl, F, C1-C6 alkyl or C1-C6-alkoxy;
• and
• R12, R13, R14 and R15 are H, Cl, F, C1-C6 alkyl or C1-C6-alkoxy;
• and
• b) a solvent.

A method of detecting a poly(amino acid), comprising the steps of:

• a) combining a sample mixture that is thought to contain a poly(amino acid) with a staining mixture that contains one or more carbazolylvinyl dye to form a combined mixture;
• wherein each carbazolylvinyl dye independently has the formula
• Q—B—Z
• where Q is a nitrogen heterocycle of the formula
• wherein
• R1 and R2 are optionally and independently H, Cl, F, sulfo, carboxy, salt of sulfo, salt of carboxy, C1-C6 alkyl or C1-C6 alkoxy;
• or R1 and R2 taken in combination form a fused 6-membered aromatic ring that is itself optionally further substituted one or more times by H, Cl, F, C1-C6 alkyl or C1-C6 alkoxy, carboxy, sulfo or salts of carboxy or sulfo;
• R3, R4, R5, and R6 are optionally and independently H, Cl, F, C1-C6 alkyl or C1-C6 alkoxy;
• or any two adjacent substituents of R3, R4, R5 and R6, when taken in combination, form a fused 6-membered aromatic ring that is optionally and independently substituted one or more times by H, Cl, F, C1-C6 alkyl, C1-C6 alkoxy, carboxy, sulfo or salts of carboxy or sulfo;
• X is —S—, —O—, —NR7—, or —CR7R8—, wherein R7 and R8 are optionally and independently H, Cl, F, phenyl, or C1-C6 alkyl;
• or R7 and R8 taken in combination complete a 5- or 6-membered saturated ring;
• TAIL is a quaternizing moiety that is attached to the nitrogen atom of Q through a carbon atom and is either —(CH2)mSO3— or —(CH2)mCO2—, where the subscript m=1 to 6 and the negative charge is balanced by a positive charge on the nitrogen heterocycle Q;
• or TAIL is —(CH2)mNRaRb or —(CH2)mN+RaRbRc, where Ra, Rb and Rc, which may be the same or different, are H or C1-C6 alkyl, or Ra and Rb taken in combination form a 3-6 membered ring that optionally incorporates a heteroatom that is O, NRd or S, where Rd is H or C1-C6 alkyl;
• and wherein any net positive charges on the dye are balanced by organic or inorganic anions;
• B is a covalent bridge having the formula —(CH═CH)n— where n=1, 2 or 3;
• and Z is carbazolyl moiety of the formula
• where
• R11 is C1-C6 alkyl or is phenyl, or is phenyl substituted one or more times by H, Cl, F, C1-C6 alkyl or C1-C6-alkoxy;
• and
• R12, R13, R14 and R15 are H, Cl, F, C1-C6 alkyl or C1-C6-alkoxy;
• b) incubating the combined mixture for a time sufficient for the carbazolylvinyl dye in the staining mixture to associate with the poly(amino acid) in the sample mixture to form a dye-poly(amino acid) complex that gives a detectable optical response upon illumination;
• d) illuminating said dye-poly(amino acid) complex;
• and
• e) observing said detectable optical response.