Morphological Characteristics of Mitochondria and Cultured Cells Made Permeable for Enzyme Studies
Toluene has been used to make various cells permeable to exogenous substrates. More recently we have extended the method to heart and liver mitochondria (1,2). We reduced the toluene concentration and included 8.5% polyethylene glycol (PEG) to stabilize these organelles (1).In this study, liver and heart isolated mitochondria and hepatoma type cells (HTC cells) in PEG were treated with either 2% or 0.1% toluene, respectively. The HTC cells were in a solution of 10% PEG, the optimal concentration indicated by biochemical data. The mitochondria were fixed in suspension in 3% glutaraldehyde in 0.1 M phosphate buffer (pH 7.3). It was necessary to add 50% gl utaral dehyde to the HTC cells in PEG-buffer to give a final 3% concentration in order to prevent gross morphological degradation determined to be a result of aqueous glutaraldehyde fixation. Following treatment, specimens were post-fixed in 1% OsO4 and prepared for electron microscopy (1,2).