Uploaded June 2023 | Updated September 2026, 14 hours ago

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You can find all my A Level Biology videos fully indexed at freesciencelessons.co.uk/a-level-revision-videos/a-level-biology

In this video, we look at how organelles are separated by cell fractionation. First we look at the roles of a homogeniser and buffer. We then look at the relative sizes of the different organelles. Finally, we explore how the organelles are fractionated by ultracentrifugation.

Image credits:

Pancreatic acinar cells
commons.wikimedia.org/wiki/File:Pancreatic_acinar_cells_-_TEM.jpg
Louisa Howard, Public domain, via Wikimedia Commons

Heart dissected
Samuel Levy, CC BY 3.0 creativecommons.org/licenses/by/3.0, via Wikimedia Commons
Homogeniser

commons.wikimedia.org/wiki/File:Tissue_glass_teflon_Dounce_homogenizer-02.jpg
Lilly_M, CC BY-SA 3.0 creativecommons.org/licenses/by-sa/3.0, via Wikimedia Commons

Centrifuge
commons.wikimedia.org/wiki/File:Multipurpose_centrifuge.JPG
Retama, CC BY-SA 4.0 creativecommons.org/licenses/by-sa/4.0, via Wikimedia Commons