allows repeated measurements in a variety of locations on the same cell without destroying the integrity of the membrane. This flexibility has been especially useful to researchers for studying muscle cells as they contract under real physiological conditions, obtaining recordings quickly, and doing so without resorting to drastic measures to stop the muscle fibers from contracting. the opportunity to examine the properties of an ion channel when it is isolated from the cell and exposed successively to different solutions on the extracellular surface of the membrane. the opportunity to examine the properties of an ion channel when it is isolated from the cell and exposed successively to different solutions on the extracellular surface of the membrane.