This MAb recognizes a 60kDa antigen associated with the mitochondria in human cells. It is a part of a new panel of reagents, which recognizes subcellular organelles or compartments of human cells. These markers may be useful in identification of these organelles in cells, tissues, and biochemical preparations. This MAb recognizes an antigen associated with the mitochondria in human cells only. 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 fixed or frozen tissue sections. It can also be used with paraformaldehyde fixed frozen tissue or cell preparations. This MAb is an excellent marker for human cells in xenographic model research. It reacts specifically with human cells, including neurons and embryonic stem cells.