Cells are tiny but complex biological machines.
Cells are the basic building blocks of all living organisms but are themselves complicated systems with many different components. Cell fractionation is the process by which cells are broken up to separate these components without disrupting their functions. Once this is done, these components (known as organelles and macromolecules) are available for analysis and experimentation. Fractionation demands some specialized skill and equipment but is a simple four-step process.
Instructions
1. Break up the cells. This can be done by vibrating them with ultrasonic waves, pushing them through a narrow orifice in a press, or grinding them in a blender. If done carefully with special lab equipment (available from laboratory suppliers), it can be done in a way that doesn't destroy the organelles within the cells. Instead, the cell-breaking process creates a slurry or "homogenate" of free-floating cell parts that can then be separated out.
2. Separate the organelles and macromolecules using a centrifuge. A centrifuge rotates a test tube full of homogenate at an adjustable speed; the centrifugal force produced by the rotation pulls the organelles outward toward one end of a tube or beaker. A lower speed will pull the heaviest organelles, such as nuclei, whereas higher speeds will pull down mitochondria and other, lighter cell components.
3. Separate the fractionated cells more exactly by adding layers of sodium or sucrose (salt and sugar) to the test tube being centrifuged. When the organelles are pulled through the layers, each type moves at a different and measurable rate, which allows researchers to isolate cell components from each other.
4. Analyse the resulting separated organelles and macromolecules. This procedure can be used to extract components as small as DNA strands, which can then be further broken down into individual nucleotide pairs. This is the basis of many different strands of scientific analysis, from the detection of genetic disorders to the tracking of evolutionary history.
Tags: organelles macromolecules, cell components, many different, test tube, these components
