Dependence of solution exchange time on cell or patch linear dimensions in concentration jump experiments using patch-clamped sensory neurones.

A critical evaluation of "concentration jump" techniques employing hydrodynamic solution exchange has been undertaken. Data obtained from experiments using acutely isolated sensory neurones demonstrated a dependence of the total solution exchange time on the linear dimensions of the preparation. The exchange time around a circular surface is proportional to the radius of this surface. A quantitative approximation can be formulated as follows: if the membrane area of the object under investigation is increased n times, the duration of the full solution exchange is increased by radical n times. A nonlinear dependence of exchange time on vacuum pressure was confirmed in a separate set of experiments.