The Seahorse XF24 is a revolutionary instrument for studies of cellular energy metabolism. This instrument measures oxygen consumption rate (OCR) and extracellular acidification rate (ECAR) of living cells simultaneously in a 24 well format. The XF24 can also measure respiration of isolated mitochondria. Kinetic measurements are made in real-time and the entire assay is completely non-invasive and requires no addition of dyes, labels or reporters. The XF24 has four injection ports per well to allow up to four test compounds (drugs or substrates) to be added automatically to each well at pre-designated times. The data collected from this instrument has been used in a variety of contexts including; glycolytic vs oxidative cancer cell metabolism, insulin resistance and obesity studies, measurement of mitochondrial quality and function, neurodegeneration, immune cell function, cardiovascular bioenergetics, aging, zebrafish respiration, pancreatic islet metabolism, and more.