DNA contamination is an important issue in a criminal laboratory, because it can impact the outcome of a case in ways which can send innocent people to jail or set free someone who is guilty. A few ways that DNA can be contaminated areÊby transfer of DNA in the lab due to improper handling and by making assumptions about the presence of DNA on an object without verifying how it may have gotten there by examining other evidence to corroborate theories.
Gel electrophoresis
Electrophoresis. Restriction enzymes are used to cut DNA into fragments. Solutions containing these fragments are placed on the surface of a gel to which an electric current is applied. The electric current causes the DNA fragments to move through the gel. Because smaller fragments move more quickly than larger ones, this process separates the fragments according to size.
The process you are referring to is called electrophoresis. In this technique, DNA fragments are loaded onto a gel matrix and an electric current is applied. The negatively charged DNA molecules move towards the positive electrode, separating based on size and charge.
Smaller DNA fragments move faster and further in gel electrophoresis compared to larger fragments. The distance migrated by DNA fragments in gel electrophoresis is inversely proportional to their size.
DNA samples are within the gel matrix during electrophoresis. DNA moves at differtent rates through the pores of the gel depending on how long the fragments are. DNA is held by the gel itself.
Gel Electrophoresis
In gel electrophoresis, DNA moves through the gel matrix from the negative electrode to the positive electrode.
Agarose gel electrophoresis is suitable for ALL DNA.
During electrophoresis, smaller pieces of DNA will migrate to the bottom of the gel first.
The bands in gel electrophoresis represent different sizes of DNA fragments.
During electrophoresis, DNA samples are placed at the wells of the gel. The gel is then subjected to an electric current, causing the DNA fragments to move through the gel based on their size.
Gel electrophoresis
gel electrophoresis
Electrophoresis. Restriction enzymes are used to cut DNA into fragments. Solutions containing these fragments are placed on the surface of a gel to which an electric current is applied. The electric current causes the DNA fragments to move through the gel. Because smaller fragments move more quickly than larger ones, this process separates the fragments according to size.
The process you are referring to is called electrophoresis. In this technique, DNA fragments are loaded onto a gel matrix and an electric current is applied. The negatively charged DNA molecules move towards the positive electrode, separating based on size and charge.
Smaller DNA fragments move faster and further in gel electrophoresis compared to larger fragments. The distance migrated by DNA fragments in gel electrophoresis is inversely proportional to their size.
In gel electrophoresis, DNA is treated with a dye that binds to the DNA molecules, making them visible as bands under ultraviolet light.