title: Harvest and storage of adult human retinal pigment epithelial sheets.
abstract: OBJECTIVE
  To describe a method for the harvesting and storing of intact viable sheets of adult human retinal pigment epithelial (RPE) cells.
  
  
  METHODS
  Adult human RPE cells were harvested as intact sheets from 21 cadaver eyes, using the enzyme Dispase. The sheets were embedded in 50% gelatin containing 300 mM sucrose and stored at 4 degrees C. The viability of the cells, as well as their ability to proliferate in vitro, was studied for 96 hours after harvesting. Light microscopy (LM), transmission (TEM) and scanning electron microscopy (SEM) were performed to determine the integrity and ultrastructural features of the cells. Microbiologic culture of the harvested sheets was performed to exclude contamination.
  
  
  RESULTS
  LM, TEM and SEM showed intact RPE cells with well-developed microvilli, basal infoldings and intercellular connections. The initial viability of intact RPE sheets was 86%, with a progressive decline in viability with increased storage time. Cells harvested within 24 hours after death maintained greater viability than those harvested after 24 hours (p < 0.05). Harvested RPE cells were free of microbial contamination and rapidly proliferated when cultured in vitro.
  
  
  CONCLUSIONS
  Intact sheets of adult human RPE can be isolated using the enzyme Dispase. The cells appeared suitable for retinal transplantation if harvested within 24 hours of death and maintained 82% viability for as long as 48 hours if stored at 4 degrees C.
authors.affiliation: Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO 63110, USA.
authors.forename: T H
authors.initials: TH
authors.lastname: Tezel
authors.forename: L V
authors.initials: LV
authors.lastname: Del Priore
authors.forename: H J
authors.initials: HJ
authors.lastname: Kaplan
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018929:Cell Culture Techniques; D002455:Cell Division; D002469:Cell Separation / Q000379:methods*; D002470:Cell Survival; D015925:Cryopreservation / Q000379:methods*; D005260:Female; D006801:Humans; D007633:Keratins / Q000378:metabolism; D008297:Male; D008855:Microscopy, Electron, Scanning; D008875:Middle Aged; D010857:Pigment Epithelium of Eye / Q000166:cytology / Q000378:metabolism / Q000648:ultrastructure; D014021:Tissue Preservation / Q000379:methods*
chemical_list: D007633:Keratins