Mitochondria are primarily separated from other cellular components using differential centrifugation.
Differential centrifugation is a two-step process that leverages the different sizes and densities of cellular organelles to isolate them. Here's a breakdown of the process:
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Low-Speed Centrifugation: The initial cell lysate (the broken-open cells) is centrifuged at a relatively low speed. This causes larger, denser components like intact cells, cell debris, nuclei, and sometimes larger organelles to pellet at the bottom of the centrifuge tube. The supernatant (the liquid above the pellet) is then carefully removed and transferred to a new tube.
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High-Speed Centrifugation: The supernatant from the first step, which contains the smaller organelles, is then centrifuged at a much higher speed. This higher speed forces the mitochondria, which are smaller and less dense than the previously removed components, to pellet. Other organelles like lysosomes and peroxisomes may also be present in this pellet, but the mitochondria are the dominant component.
In summary, differential centrifugation separates mitochondria by taking advantage of the differences in size and density between them and other cellular components through a carefully controlled two-step centrifugation process.
