Protocol for immunofluorescence characterization of drusen in induced pluripotent stem cell-derived retinal pigment epithelium cultures.

Drusen, lipoprotein-rich deposits underlying retinal pigment epithelium (RPE), are a pathological hallmark of age-related macular degeneration and related macular dystrophies. Here, we describe a protocol for visualizing drusen deposits beneath induced pluripotent stem cell (iPSC)-RPE (iRPE) monocultures. We describe steps for iRPE cell culture and, subsequently, enzymatic removal of the iRPE monolayer and immunostaining of sub-RPE drusen deposits. We then detail steps for confocal microscopy imaging of immunostained drusen in iRPE culture. For complete details on the use and execution of this protocol, please refer to Dalvi et al.(1).