Mitochondrial structure studied by high voltage electron microscopy of thick sections of Candida utilis

Mitochondrial structure in yeast cells under various physiological conditions has been studied by high voltage electron microscopy of sections that are 0-5 to 2-0 mum thick. Such thick sections of the yeast Candida utilis had a small number of long, branched tubular mitochondria per cell. The mitochondria extended into cell buds and unseparated daughter cells. It was apparent from parallel studies with thin sections that most of the rounded mitochondrial profiles viewed in thin sections should not be interpreted as being numerous small individual mitochondria. Attempts to study thick sections of the yeasts Saccharomyces cerevisiae and Schizossaccharomyces pombe were frustrated by poor contrast.