The preparation was then incubated for 30 min at 37AdC, then washed with fresh PSS. ... the stage of the microscope which had been pre-heated to 37AdC and ( Ca2+)i was analysed under a digital imaging microscope equipped ... Solutions used The PSS had the following composition (mM): 150 NaCI, 5 KC1, 1 CaCl2, 0.2 K2HPO4, 0.8 KH2PO4, 1 MgSO4, ... The high voltage and gain of the camera were kept under manual control. ... Olympus) interfaced to photometry controller units.