The facts of biology are only as good as the methods.
And the methods of molecular biology have moved on in leaps and bounds since biochemistry, genetics, and anatomical cell biology first began to coalesce in the 1930s, eventually forming what we now think of as molecular biology.
The techniques and data generated through molecular biology led to one of the most important events in biology: the revealing of the structure of DNA in 1953. Since then the field has expanded, with techniques such as PCR and western blotting the keystones of research in huge sections of the biosciences.
With the tools of molecular biology we can reveal intimate secrets of life, from the workings of the tiniest virus to the mutations and proteins that allow a tumour cell to spread throughout the body.
The facts of biology may only be as good as the methods, but something similar can also be said of the methods themselves; they are only as good as the reagents used in them. In molecular biology, whether its primers, constructs, FISH or RNA interference, good work will need good reagents.
2BScientific works with suppliers who hold themselves to the highest standards to provide researchers with the best possible reagents.
Below are just some of the applications and suppliers we have, and some information on some of the more common techniques used in molecular biology for which we supply reagents.
Molecular biology research tools include the following:
The list of techniques actually used in molecular biology is huge, as this Wikipedia article shows. A few of these techniques and some background information on them are listed below:
At its simplest, PCR is a technique for amplifying a DNA sequence from just several copies to millions of copies in just a few hours.
The basic principle of PCR was first proposed by Nobel laureate Gobind Khorana, in 1971. At that time though there was no actual way to test the principle. This was overcome in 1983 when Kary Mullis, and his colleagues, hit upon the idea of using a pair of primers to bracket the targeted DNA sequence and copy it with DNA polymerase. It wasn’t until 1985 that the more familiar heat stable taq polymerase was identified and used in PCR, greatly improving the technique.
Since then PCR has gone on to become one of the most important techniques in modern sciences, allowing rapid diagnosis of diseases such as cystic fibrosis or cancer, as well as microbial diseases. Beyond medicine its use extends to forensic science, agriculture and evolutionary biology, to name but a few.
RNAi, or RNA interference, is both a natural process and a technique used to control the expression of genes.
RNAi is, relatively speaking, a new discovery. The science grew out of the observations of plant scientists in the 1990s. Some were using transgenic plants to increase expression of certain proteins and noticed a subsequent downturn in expression, while other plant scientists were looking at plant viral defences and discovered that some plants could protect against viral infection, despite a lack of defensive proteins. A similar process was later identified in yeast.
Interest in the phenomena grew, and then in 1998 a paper published in Nature by Andrew Mellow and Craig Fire unveiled the mechanism, discovering that it was double stranded, not single, RNA that was required for the process to work. They were the first to coin the term ‘RNAi’, and their work earned them a Nobel prize.
The control of gene expression is achieved through the use of short strands of RNA – either microRNA (miRNA) or small interfering RNA (siRNA). These shorter single stranded section of RNA, typically in the range of about 12 basepairs are created from double stranded RNA. The short strands are complimentary to the mRNA product of a gene. Their complementarity allows them to bind to the mRNA preventing it’s transcription to protein, and to be cleaved by a protein called Argonaut.
RNAi is now used to probe the effects of different genes, but is also being actively developed for use as a therapeutic treatment.
Transfection is the name given to the process, done through a number of different methods, of introducing ‘new’ DNA into bacterial and mammalian cells.
Using transfection we can introduce individual genes, or other stretches of DNA, how they impact on the regulation of other genes or to force a cell to make a specific protein. As such its useful in a huge range of areas and applications, from basic cellular research to drug discovery.
Transfection can be transient, where the introduced gene is either broken down over time or becomes diluted with each subsequent generation as it is shared between daughter cells. Permanent transfection is also possible, and frequently desirable. This is usually called a ‘stable’ transfection where the cell line continues to produce the gene product, typically through incorporating the new DNA sequence into the host genome along with a second gene, for antibiotic resistance for example, which allows for selection of cells that have a stable transfection.
A number of methods are available to introduce ‘foreign’ DNA in to cells including micro-injection, electroporation, lipofection and viral transfection.