We present a protocol to electrophysiologically characterize bi-stable photopigments: (i) exploiting the charge displacements within the photopigment molecules following photon-absorption and their huge amount in the photoreceptors, and (ii) exploiting the absorption-spectra differences of rhodopsin and metarhodopsin photopigment states. These protocols are useful to screen for mutations affecting bi-stable photopigment systems.
Gutorov, R., Katz, B., Minke, B. Electrophysiological Methods for Measuring Photopigment Levels in Drosophila Photoreceptors. J. Vis. Exp. (184), e63514, doi:10.3791/63514 (2022).