Abstract: The present invention addresses the problem of providing a new compound that binds specifically to intracellular and/or extracellular vesicles, a cellular vesicle stain, and a method for fluorescent staining of cellular vesicles. The problem can be solved by a compound represented by formula (1). (In formula (1), R1 represents H, a C1-C6 alkyl group, a hydroxy group, an amino group, or a carboxy group. R2 represents H, a C1-C18 alkyl group, a C1-C18 alkoxy group, a halogen element, NO2, or N(CH3)2. R3 and R4 each independently represent H or CH3. However, R3 and R4 may bond to each other to form a ring, in which case R3 and R4 are CH2. 1 represents 1 or 2; m represents 0 or 1; and n represents 1, 2, or 3. Z represents a fluorescent group.