This MAb recognizes a 60kDa antigen associated with the mitochondria in cells. It is a part of a new panel of reagents, which recognizes subcellular organelles or compartments of cells. These markers may be useful in identification of these organelles in cells, tissues, and biochemical preparations. MAb MTC754 recognizes an antigen associated with the mitochondria in cells from a wide variety of animals including insects and bacteria. It can be used to stain the mitochondria in cell or tissue preparations and can be used as a mitochondrial marker in subcellular fractions. It produces a spaghetti-like pattern in normal and malignant cells and may be used to stain mitochondria of cells in frozen tissue sections. It can also be used with paraformaldehyde fixed frozen tissue or cell preparations.