Protocol to extract and measure ubiquinone and rhodoquinone in murine tissues

Ubiquinone (UQ) and rhodoquinone (RQ) are electron carriers for the electron transport chain (ETC). Here, we present a protocol for measuring UQ and RQ in mitochondria purified from murine tissues. We describe steps for isolating mitochondria by centrifugation, isolating UQ and RQ by biphasic extraction, and normalizing samples to the protein content of the mitochondrial pellet. We then detail procedures for analyzing UQ and RQ by integrating peak areas for UQ-9 and RQ-9 (abundant in mice) or UQ-10 and RQ-10 (abundant in human). Thus, through enrichment of mitochondria, we establish a method to measure UQ and RQ in tissues. For complete details on the use and execution of this protocol, please refer to Valeros et al.¹.