Questions and answers

What are the methods of protein extraction?

What are the methods of protein extraction?

Extraction: Depending on the source, the protein has to be brought into solution by breaking the tissue or cells containing it. There are several methods to achieve this; Repeated freezing and thawing, sonication, homogenization by high pressure or permeabilization by organic solvents.

How do detergents extract proteins?

Detergent monomers solubilize membrane proteins by partitioning into the membrane bilayer. The solubilization buffer should contain sufficient detergent to provide greater than 1 micelle per membrane protein molecule to help ensure that individual protein molecules are isolated in separate micelles.

What does detergent do to cell membranes?

Detergents effectively solubilize the phospholipid cell membrane, resulting in cell lysis. Detergents also serve to lyse the cell wall of the present bacteria. Saline (1 N) or pure water will also lyse cells [58]. Detergents, in the form of surfactants, are commonly used.

What is protein extraction?

The initial steps of protein extraction often involve crude mechanical disruption such as cutting, smashing, or shearing tissue into smaller pieces. If intracellular proteins are the target, then detergents can be used to help break apart the phospholipid cellular membrane (cell lysis).

How do you protect proteins during protein extraction?

Reducing agents: Reducing agents protect proteins against oxidative damage. They are used when extraction of specific proteins that are prone to oxidative damage is desired. Examples of reducing agents include 2-mercaptoethanol, DTT etc.

Are detergents polar or nonpolar?

Soap and detergents are quite unique molecules with the ability to dissolve in both polar and non-polar solvents. Both Soap and detergents are composed of long non-polar hydrocarbon molecules with a polar or ionic end, thus they combine both polar and non-polar characteristics in the same molecule.

What does salt solution do to extract DNA?

The salt neutralizes the negative charges on the DNA and thus enables the DNA strands to stick together. It also causes proteins and carbohydrates to precipitate.