Icrac measurement on QPatch

Rat basophilic leukaemia (RBL) cells endogenously express calcium-release-activated-calcium (CRAC) channels (Hoth and Penner, 1993). CRAC channels are activated by depletion of intracellular calcium stores, probably via the involvement of STIM-1 (stromal interaction molecule) sensing the depletion of the stores and travelling to the cell membrane activating the channel (Zhang et al, 2005; Vig et al, 2006). Several approaches can be used to deplete calcium stores ultimately leading to activation of Icrac and most of these have been tried on the QPatch. This document describes the results of these experiments and discusses the best conditions for studying Icrac with the QPatch.