We have measured the diameter (um) of freshly mitochondria isolated from rat heart using a particle size counter (Beckman Coulter Multisizer 3) and our average size is around 0.8 um. Does this value fit with some of yours using a similar method of measurement? Thanks
Maria,
Your question sparked my curiosity so I did a quick comparison of mitochondrial profiles from fixed heart muscle tissue vs isolated mitochondria profiles from the heart tissue. I say profiles because these are 2d images from TEM sectioned material. With a random selection of 10 each I came up with 695 nm (0.65 um) avg for the fixed heart tissue mitochondria and 730 nm (0.73 um) for the heart tissue isolated mitochondria that was then fixed. Only difference is first one is fixed immediately and the later was fixed after isolation. So it seems your number are in agreement with mine.
Dear Michael, thanks for your answer! That's really helpful for me.
It also depends on the location of the mitochondria, because you divide heart (muscle) mitochondria in two subpopultaions. Subsarcolemmal and interfibrillar mitochondria! We found that the subsarcolemmal were bigger than the interfibrillar.
I looked at some of my micrographs of isolated heart mitochondria, and most of the mitochondria are oblong, some are more round. They are about 800 nm long. However, isolated mitochondria are mostly fragmented and the reconstructed shape of heart mitochondria is longer, they are even branched. I also observed that, as Andrea mentioned, subsarcolemmal mitochondria are longer than interfribrillar mitochondria.
Actually, we obtain a mixture of both mitochondria sub-populations with our isolation protocol. I guess from your values that the size of our mitochondria preparation is in the normal range of mitochondria size. Thanks for your answers :)
- Badges
- Science topic
- Similar topics
- Biological Science
- Cell Biology