| 主权项 |
1. A composition comprising a substrate contacted with a live stem cell, wherein the substrate is cell permeable and is capable of being modified by an enzyme specific to the live stem cell into a modified substrate, wherein the modified substrate is both permeable and detectable such that the live stem cell can be identified by detecting the presence of the modified substrate, wherein the substrate and the modified substrate are non-toxic, and wherein the substrate is a xanthene derivative, the xanthene derivative is a fluorescein derivative, the fluorescein derivative is a fluorescein diphosphate and the fluorescein diphosphate has the structure of formula II: where: R1, R2, R3, and R4 are individually chosen from alkyl, aryl, aralkyl, heteroaryl, and heteroaralkyl; R6 and R7 are individually chosen from H, alkyl, aryl, aralkyl, heteroaryl, and heteroaralkyl; X and Y are individually chosen from H, halogen, amino alkoxy, SH, SR, alkyl, aryl, aralkyl, heteroaryl, and heteroaralkyl; Z and R5 are individually chosen from H, COOH, COOR, OH, amino, alkoxy, halogen, alkyl, aryl, aralkyl, heteroaryl, and heteroaralkyl; and m and n individually range from 1 to 3. |
