Differensialsentrifugering

Differensialsentrifugering, also known as differential centrifugation, is a laboratory technique used to separate subcellular components or different types of cells based on their size and density. The process involves a series of centrifugation steps at increasing speeds and durations.

In the initial step, a sample is centrifuged at a relatively low speed. This causes the largest and densest components, such as whole cells or nuclei, to sediment at the bottom of the tube, forming a pellet. The supernatant, containing smaller and less dense components, is then decanted and transferred to a new tube.

The supernatant is then subjected to a higher centrifugation speed for a longer period. This step pellets components that are smaller than those from the first step, such as mitochondria, lysosomes, and peroxisomes. This process is repeated multiple times, with each subsequent centrifugation step increasing in speed and/or duration to pellet progressively smaller and less dense components, like ribosomes, microsomes, and finally, soluble proteins in the final supernatant.

The resulting pellets can be collected and further analyzed to study the biochemical composition and function of specific cellular organelles. Differensialsentrifugering is a fundamental technique in cell biology and biochemistry for isolating and purifying various cellular fractions. While effective for separating components with distinct size and density differences, it may not achieve complete separation of very similar particles and can sometimes lead to contamination between fractions.