Dyes for monitoring cell states

A method for determining whether an agent induces a change in a cell phenotypic state comprising detecting the fluorescence of a dye compound of formula (I):

• wherein:
• R1 is H, alkyl, substituted alkyl(C≤14), alkenyl(C≤14), substituted alkenyl(C≤14), aryl, or substituted aryl;
• R2 is H, alkyl, substituted alkyl(C≤14), alkenyl(C≤14), substituted alkenyl(C≤14), aryl, or substituted aryl;
• R3 is hydrogen, Cl, Br, F or CX3;
• R4 is hydrogen, Cl, Br, F or CX3;
• R5 is hydrogen, Cl, Br, F or CX3;
• R6 is hydrogen, Cl, Br, F or CX3;
• R7 is hydrogen, Cl, Br, F or CX3;
• and
• R8 is —(CH2)nSO3−, —(CH2)nN+(R9)3 or
• wherein
• R9 is alkyl(C≤14), substituted alkyl(C≤14), aryl, or substituted aryl;
• Y is H or OH;
• W is
• X is H, F, Cl, or Br;
• and
• n is 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10;
• and
• wherein the dotted lines indicate the presence or absence of a phenyl ring or a substituted phenyl ring, wherein the substituent may be one or more selected from Cl, Br, F, CX3, alkyl(C≤14), and substituted alkyl(C≤14),
• or a salt thereof;
• in the cell in the presence or absence of the agent, wherein a change in the florescence intensity and/or distribution in the cell in the presence of the agent relative to the absence thereof is indicative that the agent induces a change in the cell phenotypic state.