In vivo staining of the mammalian retina by means of a simple fluorescent method

Abstract

Intraocular injections of microliter volumes of a solution containing the fluorescent stain Fluoro-Gold produces an intense and long-lasting in vivo stain of the cells forming the neural retina of rats and mice. The label is incorporated by the neuro-retinal cells. while other intraocular structures such as the lens, iris, ciliary processes and even the optic nerve head exclude it. The fluorophore can be easily demonstrated under epi-illumination by means of commonly used fluorescence filter combinations. The stain has proven to be compatible with cryostat sectioning and with plastic embedding. Furthermore, electron dense lysosomal and lamellar bodies in retinal neurons which have incorporated the stain may provide a means for identification of Fluoro-Gold labeled cells at the electron microscopic level which is consistent with previous results. Intraocular injection of Fluoro-Gold fills the need for a reliable, simple, and robust in vivo and in toto stain of the neural retina.