Sulcardine sulfate

Two-electrode voltage clamp measures whole-oocyte membrane current from Xenopus oocytes expressing exogenous ion channels, receptors, or transporters; one intracellular microelectrode senses membrane voltage, and the second injects current so the amplifier can hold the membrane at command voltages while recording the compensating current as the functional readout. The method is suited to Xenopus oocytes because their large size supports microinjection and intracellular electrode impalement, but the large membrane area can limit voltage-clamp speed and accuracy, especially for large or fast currents.

Ca²⁺ staining is an experimental technique that utilizes specific fluorescent probes (such as Fluo-4 AM, Fura-2, etc.) to qualitatively or quantitatively detect dynamic changes in intracellular Ca²⁺ concentrations; this is achieved by monitoring the changes in fluorescent signals generated when these probes bind to free intracellular calcium ions. The underlying principle relies primarily on the presence of chelating groups within the probe's molecular structure that possess high affinity for calcium ions.