The SURFE2R Stimulating Optical Lid (SOL) replaces our standard lid for the measurement chamber. The optical lid contains a plate with an integrated LED ring - exchangeable within seconds and available in eight different wavelengths. The LED may be used to study light-gated channels or light-driven pumps such as Channelrhodopsin or Bacteriorhodopsin. But it can also be applied to study the voltage dependence of other transporter targets through voltage generation via light-triggered electrogenic transporters or channels. Usually, the SURFE2R applies a solution exchange providing a substrate to activate the transporter and record the resulting transient transporter current. Now substrate and light activation can be used individually, or a combination of light and substrate stimuli enables experimental designs which were never seen before. Besides the stimulating optical lid itself, the add-on comes with new internal electronics and a powerful software upgrade to control the LEDs: We developed a new workflow editor which can be used to set several experimental parameters such as light intensity, and to switch between continuous and pulse modes.
