Just looking for the myriad features that should show up in mitochondrial ultrastructure. THis isolated mitochondrion is from a wild type mouse post natal day 14, liver.  It does show areas where cristae membranes (inner mitochondrial membrane) and outer mitochondrial membranes create the inner mitochondrial membrane space (green) and the membranes themselves (pink) and the matrix (blue).  Within the texture of the matrix it is tempting to try to find circular mDNA and mitoribosomes and there are hints of them here but nothing really obvious shows up. Trying to find some difference in inner mitochondrial membrane density which would indicate the crista junction is pretty disappointing as well.  Not all structures named, or presumed to be real, can be found in routine micrographs. There is one little circular structure in the middle of the matrix which I might well have included as cristae membrane.