Video Transcript
The picture provided shows a centrifuge, which can separate cell components using
cell fractionation. Why is cell fractionation useful to scientists? (A) Harmful cells, like pathogens, can be destroyed to prevent them from infecting
humans. (B) Cell fractionation can be used to separate different types of cells from the same
tissue. (C) Cell fractionation allows specialized cells to be created from undifferentiated
ones. Or (D) organelles and other cellular components can be studied in more detail once
separated.
To answer this question, let’s start by recalling the scientific procedure called
cell fractionation. Cell fractionation is the process used to separate cellular components without
deteriorating them. This is a very common method that is typically used by scientists to separate
cellular components in order to study them in more detail. This procedure involves two main steps. First, scientists prepare a cell suspension in a physiological solution that mimics
the cell environment. Then cells are mechanically separated using a homogenizer or grinder. The resulting homogenate contains the cell components and organelles.
Then the cell homogenate is centrifuged several times, with increasing speed of
centrifugation. This separates the homogenate into a pellet at the bottom of the tube and the
supernatant, which is the solution. Then the supernatant solution is centrifuged again, and the procedure is repeated
several times. This separates the different cellular components based on their different
densities. The different components are collected sequentially in the pellet obtained at the
bottom of the tube after each centrifugation.
Note that centrifugation can also be used to separate different types of cells
present in a tissue that has been homogenized. But in this case, the cells themselves are not broken. This procedure is not called cell fractionation. So we can rule out option (B) to answer our question. Instead, the correct answer to the question “Why is cell fractionation useful to
scientists?” is answer (D). Organelles and other cellular components can be studied in more detail once
separated.
