Intravitreal Injection of Peanut Agglutinin Results in Specific Labeling of Long-Wave-Length-Sensitive Cone Photoreceptors (pp. 163-170)
Authors: (Makoto Ishikawa, Takeshi Yoshitomi, Department of Ophthalmology, Akita University Faculty of Medicine, Hondo, Akita, Japan)
Abstract: Purpose. To investigate whether intravitreally injected fluorescein (FITC)-conjugated peanut agglutinin (PNA) can be specifically bound to long-wavelength-sensitive cone photoreceptor outer segment membrane.
Methods.Two microliters of FITC-PNA (100μg/ml) was intravitreally injected into dace. After two hours, the retinas were removed, and mounted on the slide glass. To isolate the PNA-positive photoreceptor cells, the flat mount retinal preparations were mechanically compressed under the cover glass. Specificity of PNA-labeling was examined by simultaneous flurescence and Nomarsky interference microscope.
Results. By the application of intravitreal injection of FITC-PNA, the flat mount preparation showed regular arrangement of cone mosaic. The mechanical isolation procedure revealed that the outer segment of the long-double-cone and the long-single-cone photoreceptor cells were fluorescent positive.
Conclusions.Intravitreally injected FITC-PNA results in specific labeling of outer segment of the long-wavelength-sensitive cone photoreceptors in vivo.Our results provide an efficient method for quantitative analysis of cone mosaic patterning.