Abstract
Mitochondria participate in series of metabolic processes and cellular events. It is widely known that only 13 proteins are encoded by the mammalian mitochondria genome. However, it is not acknowledged until recently that mitochondrial genomes encode hundreds of circular RNAs, named as mecciRNAs. Some of these mecciRNAs can serve as molecular chaperones to help folding nuclear-encoded proteins and facilitating their mitochondrial entrance. As a novel type of circular RNAs, functions and characteristics of mecciRNAs are waiting for further exploration and methods for mecciRNA studies need to be improved. Here, we describe detailed methods for mitochondrial RNA isolation and mecciRNA detection. In addition, we present effective mecciRNA overexpression and knockdown strategies for future functional studies of mecciRNAs.