User:Books&coffee/Molecular Biology

Edit Summary
Sections initially copied from Molecular biology.

Lead Section (transferred to live article)
Molecular biology /məˈlɛkjʊlər/ is the branch of biology that seeks to understand the molecular basis of biological activity within and between cells, including molecular synthesis, modification, mechanisms, and interactions. Molecular biology also plays a critical role in the understanding of structures, functions, and internal controls within individual cells, all of which can be used to efficiently target new drugs, diagnose disease, and better understand cell physiology.

Molecular biology is not simply the study of biological molecules and their interactions; rather, it is also collection of techniques developed since the field's genesis which have enabled scientists to learn about molecular processes. One notable technique which has revolutionized the field is the polymerase chain reaction (PCR), which was developed in 1983. PCR is a reaction which amplifies small quantities of DNA, and it's used in many applications across scientific disciplines, as will be discussed later.

The central dogma of molecular biology describes the process in which DNA is transcribed into RNA, which is then translated into protein. Molecular biology was first described as an approach focused on the underpinnings of biological phenomena - uncovering the structures of biological molecules as well as their interactions, and how these explain observations of classical biology.

Some clinical research and medical therapies arising from molecular biology are covered under gene therapy whereas the use of molecular biology or molecular cell biology in medicine is now referred to as molecular medicine.

The Bradford Assay
The Bradford Assay is a molecular biology technique which enables the fast, accurate quantitation of protein molecules utilizing the unique properties of a dye called Coomassie Brilliant Blue G-250. Coomassie Blue undergoes a visible color shift from reddish-brown to bright blue upon binding to protein. In its unstable, cationic state, Coomassie Blue has a background wavelength of 465 nm and gives off a reddish-brown color. When Coomassie Blue binds to protein in an acidic solution, the background wavelength shifts to 595 nm and the dye gives off a bright blue color. Proteins in the assay bind Coomassie blue in about 2 minutes, and the protein-dye complex is stable for about an hour, although it's recommended that absorbance readings are taken within 5 to 20 minutes of reaction initiation. The concentration of protein in the Bradford assay can then be measured using a visible light spectrophotometer, and therefore does not require extensive equipment.

This method was developed in 1975 by Marion M. Bradford, and has enabled significantly faster, more accurate protein quantitation compared to previous methods: the Lowry procedure and the biuret assay. Unlike the previous methods, the Bradford assay is not susceptible to interference by several non-protein molecules, including ethanol, sodium chloride, and magnesium chloride. However, it is susceptible to influence by strong alkaline buffering agents, such as sodium dodecyl sulfate (SDS).