Polyacrylamide gel is a commonly used solution in electrophoresis to separate molecules based on charge and size. It contains acrylamide, water, a buffer, ammonium persulfate, and TEMED. The concentration of acrylamide determines the separation of smaller molecules. It is used for protein and DNA separation, and the hardness of the gel determines the amount of friction. DNA and protein separation is done using a standard to determine the size of the strands.
Polyacrylamide gel is a solution commonly used in electrophoresis, the process of separating molecules or particles of different sizes by passing them through a gel and applying an electric current. There are several recipes for polyacrylamide gel, but it typically contains acrylamide, water, a buffer, ammonium persulfate (APS), and tetramethylethylenediamine (TEMED). This gel works as a matrix that separates compounds based on their charge and size; the more acrylamide in the gel solution, the better the separation of smaller molecules. Typically this gel is used for protein and DNA separation.
In electrophoresis, an electric field causes charged particles to move through a gel, which works like a sieve to separate particles of different sizes. The gel will absorb the heat produced by the electric current. Polyacrylamide gel is commonly used in these procedures, but agarose, another chemical that creates a similar gel, can also be used.
The gels can be made in variable concentrations, with amounts of acrylamide ranging from about 6% to 15%. When you mix the gel, the acrylamide is uncured, meaning it remains as single molecules. The addition of other bond-promoting chemicals, such as TEMED, causes the molecules to bind together forming long chains, the “poly” part of the polyacrylamide.
The main advantage of polyacrylamide gel is that the number of bonding links and hardness can be controlled based on the initial amount of acrylamide and TEMED added. A major factor in acrylamide concentration is the size of the molecule being analyzed. The smaller the compounds that are separated, the more acrylamide is needed; very small particles are separated using the highest concentration, 15%.
Acrylamide works by controlling the amount of friction in the gel; the hardness of the gel determines the amount of friction. Large compounds will move more slowly through the gel as there is naturally more friction or resistance due to their size. Smaller compounds move faster, as there is less friction. To keep small compounds from breaking away from the gel, more acrylamide is added to create more friction.
DNA polyacrylamide gel is used to separate DNA strands of different lengths. Pieces of DNA will separate from just one nucleotide, the compounds that make up each strand. To know which pieces relate to specific dimensions, a standard is commonly made which contains fragments of known size along with samples. The DNA pieces are then compared to the standard and the strand size is determined.
A similar procedure is used to determine the size of proteins, most often those in the blood. Blood contains two main types of protein: globulin, a large protein, and serum albumin, a very small, negatively charged protein. Polyacrylamide gel separation is used to determine the amount of each type.
Protect your devices with Threat Protection by NordVPN
