What is a marker of molecular weight?
The molecular weight marker is a molecule used to provide an estimate of the size of the molecules of subjected gel electrophoresis. This is a technique in which DNA, RNA or proteins are separated by size by electric current to the gel. This term should not be confused with molecular markers in genetics - an area in which the DNA of the organism differs from the rest of the population and can be identified by DNA probe. The molecular weight marker is a group of proteins of a known molecular weight that is generally provided by biotechnology companies to a certain size extent. One chooses the size range based on studied samples. Molecular weight marks are loaded together and separate during the run. By measuring the distance of marker and protein that is interesting, the size of the experimental protein can be determined.
different types of marks can be visualized in different ways. Some of the molecular markers are unmarked and are colored in a gel with the rest of the proteins. Are not visible,until the whole gel is colored. Other types of molecular protein markers are pre -colored with colors and each type of protein is a different color. Separation is visible when the gel is running.
One of the advantages of the pre -colored marker of the molecular weight is for the western blot. It is a technique in which the proteins are transmitted to the membrane and then colored with antibodies to detect a particular protein. Using color marks, it helps to determine whether the protein transmission is completed before one proceeds with the rest of the procedure.
Molecular weight markers are commonly used to analyze DNA on gels. DNA molecular markers are often made of bacterial virus lambda . The enzyme limitations are produced by bacteria for DNA of invasive organisms and the restriction enzyme hindiii is often used to degrade lambda DNA. Creates a number of different, reproducible fragments known as DNA ladder . By comparing the distance operated according to the standards on the logarithmic scale, the size of the analyzed DNA fragments can be determined.
This marker of DNA molecular weight can be used to analyze DNA size produced during gene isolation and genetic engineering experiments. It can also be used during polymerase chain reactions (PCR), in which amplified small amounts of DNA or RNA to form a large amount of product. PCR techniques are commonly associated with paternity testing and forensic science, but are also very common in medical and basic biological research. Special markers of molecular weight are available for smaller products generated from some types of PCR or small RNA molecules.