Methods and compositions for assessing cell viability

A compound of Formula I:

• D-L-R (I)
• wherein:
• D is a fluorescent moiety;
• L is a linker;
• and
• R is Formula IA or Formula IB:
• —B—N(R1)(R2) (Formula IA),
• wherein B is a bond, an aliphatic group or an aromatic group;
• and
• R1 and R2 are each independently ethyl substituted with a Z at the 2 position or substituted ethyl further substituted with a Z at the 2 position, and each Z is independently OH, Cl, Br, I or
• where R5 is alkyl, substituted alkyl, aryl or substituted aryl;
• or
• -A-Pt(X)(R3)(R4) (Formula IB),
• wherein A is a heterocycloalkyl or substituted heterocycloalkyl in which a nitrogen is bonded to the platinum of Formula IB;
• the substituents of the platinum of Formula IB are in a square planar configuration with R3 and R4 in cis;
• X is Cl, Br, or I;
• R3 and R4 are each independently —NH2R6, wherein R6 is H, C1-6 alkyl, or substituted C1-6 alkyl;
• or R3 and R4, together with the platinum of Formula IB, form a ring in which the two atoms bonded to the platinum are nitrogen and the ring comprises at least two carbons between the nitrogens.