Molecular Biology

Molecular biology is closely related to the fields of Cell Biology, Microbiology, Biochemistry, Genetics, Pharmaceuticals, Bioengineering and Biotechnology.  Molecular biology is the area of biology dealing with the molecules and molecular processes that form the underlying basis of life.  The primary focus of molecular biology is on proteins and nucleic acids (DNA and RNA).

Most findings in molecular biology are quantitative in nature; the field has given rise to Bioinformatics, Computational Biology, and Molecular Genetics.  One of the emerging offshoots of molecular biology is Molecular Evolution, which is the study of evolutionary processes at the molecular level.

Scientists have a deep interest in the study of cellular macromolecules.  An in-depth understanding of fundamental structures and processes aids in the comprehension of disease-causing factors and the development of suitable treatments.  In addition to curing disease, molecular biology techniques can assist in the creation of organisms exhibiting desired traits, such as disease resistance, plants with an increased yield, and bacteria with altered protein expression.  Molecular Biology techniques can be used to manipulate genetic code of an organism.

Applications of Molecular Biology

Molecular biologists have developed several techniques to extract, amplify, and quantify cellular molecules.  Relevant equipment, protocols and necessary reagents are also easily available on the internet and for purchase from vendors.  Many contract research organizations (CROs) are offering molecular biology services.  Arrays, expression cloning, Northern blotting, cloning, polymerase chain reaction (PCR), Western blotting, and gel electrophoresis are some frequently used molecular biology techniques.

A western blot utilizes a gel to separate molecules based on size. The molecular biology technique has been highly useful in protein isolation and research.


PCR is the technique used for the in situ creation of millions of copies of a specific DNA sequence.  This efficient technique bypasses the need to use bacteria to replicate the amount of DNA.  Briefly, a single strand of DNA is used as a template for duplication.  The newly created copy in turn is then replicated in the next temperature cycle, and so on, until there is exponential amplification of the starting template.  As the name implies, DNA growth through PCR is akin to a chain reaction.

Expression cloning

Expression cloning is a technique referring to the cloning of a DNA sequence that produces a specific protein.  A DNA insert containing the gene of interest is inserted into a circular plasmid and then introduced into host cells.  The plasmid then transcribes and translates the inserted gene sequence, whose protein production may be enhanced by using appropriate promoters.  The overexpressed protein is then isolated and used in further characterization studies.

Western Blot

The Western blot assay is able to detect a single protein in a mix of proteins, much like an ELISA.  It requires an antibody that is specific to the target protein to be detected.  However, unlike an ELISA, a Western blot is not performed in a well plate, and involves separation by molecular weight.  By using an automated Western blotting system, the highly sensitive and automated system can run up to 25 samples simultaneously, utilizing a microcapillary system.