title: Trypan blue induces apoptosis in human retinal pigment epithelial cells.
abstract: OBJECTIVE
  To examine whether trypan blue dye induces apoptosis in human retinal pigment epithelium cells.
  
  
  METHODS
  Laboratory investigation.
  
  
  METHODS
  Pure cultures of human retinal pigment epithelium cells were isolated. The cells were incubated with different concentrations of trypan blue (0.5%, 0.10%, and 0.05%) for either 5 or 30 minutes. The rate of retinal pigment epithelium cell apoptosis was assessed with Annexin V-PE staining and flow cytometry.
  
  
  RESULTS
  Trypan blue induced a statistically significant amount of apoptosis in retinal pigment epithelium cells at all the concentrations (0.5%, 0.10%, and 0.05%) (P <.05). The increase in incubation time (from 5 to 30 minutes) led to an increase in the number of apoptotic retinal pigment epithelium cells.
  
  
  CONCLUSIONS
  The incubation of retinal pigment epithelium cells with trypan blue increased the number of apoptotic retinal pigment epithelium cells in vitro. Our results suggest that decisions regarding the intravitreal application of trypan blue dye need to be made with caution.
authors.affiliation: Department of Ophthalmology and Visual Science, University of Chicago, 5841 S. Maryland Avenue, MC-2114, Chicago, IL 60637, USA. karezaei@yahoo.com
authors.forename: Kourous A
authors.initials: KA
authors.lastname: Rezai
authors.forename: Lili
authors.initials: L
authors.lastname: Farrokh-Siar
authors.forename: Elzbieta M
authors.initials: EM
authors.lastname: Gasyna
authors.forename: J Terry
authors.initials: JT
authors.lastname: Ernest
mesh_terms: D017304:Annexin A5 / Q000378:metabolism; D017209:Apoptosis / Q000187:drug effects*; D002478:Cells, Cultured; D004396:Coloring Agents / Q000494:pharmacology*; D005434:Flow Cytometry; D006801:Humans; D010857:Pigment Epithelium of Eye / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D014343:Trypan Blue / Q000494:pharmacology*
chemical_list: D017304:Annexin A5; D004396:Coloring Agents; D014343:Trypan Blue