In the bone marrow, immature RBC's mitochondria surround the nucleus and get laden with excess iron deposits, which produces ringed sideroblasts on histology, hence the name of the disease.
When compared to eukaryotic cells, the structure of bacteria is less complex due to a lack of nucleus and membrane-bound organelles such as mitochondria, endoplasmic reticulum, and Golgi complexes.
In addition, most of the intracellular calcium is stored within organelles like the mitochondria and smooth endoplasmic reticulum and is released selectively just when it's needed.
Her technique involved infusing the site of the ischemia-inducing blood clot with mitochondria as part of an otherwise-standard procedure to remove the clot.