he Cedars-Sinai Metabolism and Mitochondrial Research Core provides comprehensive services for analysis of metabolism and mitochondrial function in the research setting. Instrumentation includes a Seahorse XF24 Extracellular Flux Analyzer for measurement of oxygen consumption rate (OCR) and extracellular acidification rate (ECAR) in order to interrogate changes in oxidative phosphorylation and glycolysis in cells or isolated mitochondria. This bioenergetic analysis allows testing multiple conditions per assay well and direct, simultaneous comparisons across wells, enabling faster throughput with smaller samples compared with traditional respirometry methods. We also have a Seahorse XFp, which is ideal for experiments involving only a few samples or with limiting amounts of material. Like the XF24, the XFp can monitor oxygen consumption rate and extracellular acidification rate. It is ideal for pairwise comparisons, bioenergetic phenotyping and analysis of patient-derived samples (e.g., biopsies). The Seahorse work area (200 square feet) also includes a biosafety cabinet and tissue culture incubator for cell culture plates, to be used with the Seahorse instruments. A Keyence BZ-9000 fluorescence microscope with user-friendly software for rapid image acquisition and advanced functions including 3-D deconvolution, image stitching and quantitative image analysis is also available through the core.

The core also has instrumentation for assessment of whole body and tissue composition of fat/lean/water mass using proton magnetic resonance spectroscopy (Echo Medical System; 100 square feet, Davis Building), and metabolic cages (Oxymax Lab Animal Monitoring System, Columbus Instruments; 100 square feet, Davis vivarium) for measurement of food intake, energy expenditure, respiratory exchange ratio and physical activity. Noninvasive determination of the respiratory exchange ratio allows assessment of energy expenditure and substrate (glucose versus fatty acid) utilization. The metabolic cages can also be used for quantitative measurement of movement (XY-axis) as an index of physical activity and for assessment of food and water intake over a given period of time (typically three to five days).