Combining Suction-Pipette Spectral Identification With Single-Cell RT-PCR to Make Differential Analyses of Amphibian Red and Green Rods.

Amphibian retinas contain "green" rods, which are rod-shaped photoreceptors with a cone-type visual pigment. These rods are considered a potentially transitional photoreceptor type, but their phototransduction cascade's molecular composition has remained uncertain. Here, we present a streamlined electrophysiology-molecular workflow that enables the rapid spectral identification, physical capture, and targeted single-cell reverse transcription-polymerase chain reaction (RT-PCR) of individual amphibian photoreceptors. After suction-pipette spectral screening under alternating red and green illumination, electrophysiologically identified cells are isolated and processed directly for reverse transcription and PCR. Coupling real-time functional phenotyping with sensitive molecular profiling provides a practical tool for resolving photoreceptor molecular heterogeneity and investigating evolutionary transitions between rod and cone phenotypes. Key features • New combined workflow: Rapid electrophysiological spectral typing by suction-pipette, followed by single-cell transfer, reverse transcription, and targeted PCR.