Correct option is B
Rate-zonal centrifugation is a type of density gradient centrifugation used to separate molecules based on their size and mass while maintaining structural integrity. This method requires a density gradient medium, which allows different molecules to sediment at different rates depending on their mass.
- Sucrose is the most commonly used gradient medium in rate-zonal centrifugation.
- continuous density gradientIt forms a , allowing molecules to move based on their size.
- proteins, ribosomes, and subcellular organellesSucrose gradients are ideal for separating like lysosomes and microsomes.
- non-toxic, water-soluble, and does not interfereIt is with biological molecules.
Information Booster:
- Rate-zonal centrifugation relies on size differencesisopycnic centrifugation, while separates molecules by density.
- A pre-formed sucrose gradient is required, with increasing sucrose concentration from top to bottom.
- Sample is carefully layered on top to avoid mixing.
- Centrifugation speed and duration affect separation efficiency.
- Fractions are collected from the bottom after centrifugation for analysis.
- Other gradient media used include Percoll, Ficoll, and cesium chloride, but sucrose is the most common.
- Common applications include isolating ribosomes, viruses, and organelles like mitochondria.
Additional Information:
Option 1 (Phospholipids - Incorrect):
Option 3 (KCl - Incorrect):
- Phospholipids do not form a suitable density gradient and are mainly involved in membrane structures.
Option 4 (Starch - Incorrect):
- Starch is insoluble in water and does not form the required continuous gradient.
- Potassium chloride is used in osmotic balance and cell lysis buffers, but not for gradient formation.
