In the late 1970s, the BPAE cell line was established by Paul Del Vecchio from the pulmonary artery of a young cow (Bos taurus). BPAE cells exhibit endothelial morphology and test positive for bovine diarrhea virus, a pathogen that regularly results in significant economic losses in the beef industry. The cells are also positive for angiotensin converting enzyme (ACE), which functions importantly in the maintenance of blood pressure and volume. Because of the role of ACE, BPAE cells are especially useful in studies of hypertension, atherosclerosis, and coronary heart disease.

When present in the body, endothelial cells are usually elongate in shape and arranged with their long axes in parallel orientation with the blood flow direction. Two different types of connections, known as gap junctions and tight junctions, link the cells closely together. Adjacent endothelial cells are able to communicate via gap junctions, which allow small molecules and ions to pass directly from one cell to another. Tight junctions, however, function as barriers to the diffusion of most molecules. A tight junction forms a band around the entire circumference of a cell.

To visualize mitochondria in a monolayer BPAE culture (illustrated above), the bovine pulmonary artery cells were treated with MitoTracker Red CMXRos, a derivative of X-Rosamine. Cell nuclei were targeted with the popular nuclear counterstain SYTOX Green. Images were recorded in grayscale with a 12-bit digital camera coupled to a Nikon Eclipse 80i microscope equipped with bandpass emission fluorescence filter optical blocks. During the processing stage, individual image channels were pseudocolored with RGB values corresponding to each of the fluorophore emission spectral profiles.