Protocol for optogenetic control of cAMP in human telencephalic organoids using an easy-to-build Arduino-driven LED system.

Temporal regulation of cyclic adenosine monophosphate (cAMP) using photoactivated adenylyl cyclase (bPAC) is critical in research; however, commercial optogenetic systems are costly. Here, we present a protocol for optogenetic control of cAMP in human telencephalic organoids using an easy-to-build Arduino-driven light-emitting diode (LED) stimulation system. We describe steps for assembling the system, writing code for LED regulation, and preparing induced pluripotent stem (iPS) cells for optogenetic experiments. We then detail procedures for optogenetic activation of cAMP to control cell-fate decisions. For complete information on the generation and use of this protocol, please refer to Shimada et al.1.