Cut-Open Oocyte Voltage-Clamp Technique
The cut-open oocyte Vaseline gap (COVG) voltage clamp technique, a relatively recent addition to the electrophysiologist’s armamentarium, was specifically developed by Drs. Stefani and Bezanilla (Bezanilla et al. 1991) to achieve low-noise recordings of the membrane of Xenopus laevis oocytes with fast clamp speed and thus optimize the most popular transient expression system to reveal the activity voltage-dependent proteins previously difficult to resolve by alternative methods. The high degree of specialization of this technique is complemented by its flexibility; in addition to oocyte perfusion, COVG can be combined with optical measurements (voltage clamp fluorometry and spectroscopy) and flash photolysis for the instantaneous release of intracellular caged compounds, expanding its use beyond electrophysiology.
During the cloning era, the oocytes of the African clawed frog (Xenopus laevis) emerged as a powerful biological tool, as their large size (≈1...