Abstract: The present invention relates to fluorescent dyes of formula (I), including salts thereof, and extracellular vesicles and cells labelled with the fluorescent dyes. The present invention also relates to methods, uses and kits thereof.

Abstract: The present invention relates to phyllochlorin analogues and their pharmaceutically acceptable salts, and compositions comprising phyllochlorin analogues and their pharmaceutically acceptable salts. Phyllochlorin analogues and pharmaceutically acceptable salts thereof are suitable for use in photodynamic therapy, cytoluminescent therapy and photodynamic diagnosis, for example, for treating or detecting a tumour, so or for antiviral treatment. The present invention also relates to the use of phyllochlorin analogues and pharmaceutically acceptable salts thereof in the manufacture of a phototherapeutic or photodiagnostic agent, and to a method of photodynamic therapy, cytoluminescent therapy or photodynamic diagnosis, for example, for treating or detecting a tumour, or for antiviral treatment.