Comparison of formaldehyde and methanol fixatives used in the detection of ion channel proteins in isolated rat ventricular myocytes by immunofluorescence labelling and confocal microscopy

Abstract

In this study, a fixation protocol using a 10% neutral buffered formalin (FA) solution and another protocol using a methanol (MeOH) solution were compared for detection of ion channels, K_v1.5, K_v4.2, Ca_v1.2, K_ir6.2, Na_v1.5 and Na_v1.1 in rat myocytes by immunolabelling. K_v1.5 and K_v4.2 at intercalated discs and Ca_v1.2 at transverse tubules were not detected by FA but were detected by MeOH. K_ir6.2 at transverse tubules and Na_v1.5 at sarcolemma were detected by FA but not by MeOH. It is suggested that both FA and MeOH fixation protocols should be used for the detection of cardiac ion channels by immunolabelling