The industrial centrifuge plays an integral role in the production of more things than one would initially expect. It is a commonly used tool in the food and agricultural sector, At pharmaceutical and biotechnology companies, for environmental management, and in the chemical industry. The word industry conjures up images of combination and creation—adding materials together to produce a final product. However, the separation of materials is just as important as the combination of materials. We can't create a new product until we have pure reactants to work with. This is especially important in the pharmaceutical and biotechnological realms, where reactant purity is essential to the production of a product that is safe for human consumption. This is where the centrifuge comes in. The centrifuge is used to separate heterogeneous mixtures into components varying by density.
Antibodies are an important part of the immune system. When the body is infected with an antigen, the immune system generates an antibody specific to that antigen. The techniques that are routinely used in biotechnology capitalizes upon this natural immune process. Antibodies are used in many research applications as well as in immunoassays for disease detection. We use the specificity of the antigen/antibody binding for immunoprecipitation and ELISA assays. We use flurophore-conjugated or enzyme-tagged antibodies for labeling molecular targets on individual cells and whole tissue. We use antibody purification to obtain antibodies for biosensors to detect disease. These antibodies, depending on the application, are commonly obtained by antibody purification from humans, rats, rabbits, mice, and chicken.
A gst fusion protein (Glutathione-S-transferase) is useful for affinity chromatography and immunoprecipitation. The natural form of GST is an enzyme that catalyzes the protective mechanisms of glutathione. Glutathione is an antioxidant that prevents cell damage by reactive oxygen species. However, the GST fusion protein is not natural. It is a genetically engineered protein that has become a useful biotechnological tool.
The affinity between the GST fusion protein and glutathione is what makes it useful for affinity chromatography. Once a capture GST fusion protein is created, it can be used to capture a target protein, and the whole complex can be isolated by running it through a glutathione column. The complex is then eluted by adding an excess of glutathione, which out-competes the bound glutathione and fills the GST binding site resulting in release from the column.
Gold nanoparticles display unique optical properties. These properties make gold nanoparticles useful tools for biotechnology and medicine. Gold nanoparticles are also called nano gold or colloidal gold due to the fact that they are less than 100nm in size and are suspended in a liquid solution. The color of the colloidal gold is dependent upon the size and shape of the gold nanoparticles comprising it. Larger particles and aggregates of particles cause the absorbance spectrum to broaden and shift towards longer wavelengths and a red color. The metallic nature of the particles makes them very useful for imaging by electron microscopy, which was one of the first applications for them. The gold nanoparticles can be functionalized with antibodies, carbohydrates, and nucleic acids. This makes them very useful for scanning electron microscopy (SEM), transmission electron microscopy (TEM), and confocal light microscopy as well as pathogen detection and other diagnostic assays. The ability of gold to absorb light via surface plasmon resonance (SPR) makes them useful tools for photothermal therapy in the treatment of cancer.
An in vitro diagnostic product (IVD) is any reagent, device, system, or part of a system used outside of the body to diagnose a disease or infection. The IVD can be used to detect DNA/RNA, microorganisms, or protein. This can be in a laboratory setting or in a “point of care setting.” Point of care (POC) is beneficial because it removes the need to send a sample to a laboratory for testing. Therefore, the time between sample collection and diagnosis is significantly reduced. Point of care IVD is especially useful in resource-poor settings where laboratories are located far away and there is a lack of good communication or transportation infrastructure.
The sandwich ELISA is a type of Enzyme-linked immunosorbent Assay that uses two antibodies: a capture antibody and a detection antibody. The purpose of any ELISA is to detect the presence of a target antigen in a sample. In a sandwich ELISA the target antigen is bound between a capture antibody and a detection antibody. The capture antibody is immobilized on a surface, while the detection antibody (conjugated to an enzyme or fluorophore label) is applied as a last step before quantitation.
Filtration is a simple technique used to separate solid particles from suspension in a liquid solution. There are many filtration methods available, but all are based on the same general principle: a heterogenous mixture is poured over a filter membrane. The filter membrane has pores of a particular size. Particles larger than the pores will be unable to pass through the membrane, while particles smaller than the pores will pass through unhindered. Additionally, all liquids will pass through. The final result of a filtration process is a collection of residue on the filtration membrane. This residue is therefore effectively separated from the rest of the mixture that passed through the membrane.
Biotinylation means attaching a biotin tag to a molecule. Biotin is a natural molecule that is also known as vitamin B7. It is an important component in a healthy diet, but it is also very useful in the laboratory in a method for protein conjugation. In the laboratory, he purpose of biotinylation is to create a controlled site for biotin-streptavidin affinity binding. Biotin and streptavidin have an extraordinary affinity for each other (Kd=10^-15). With such a low dissociation constant, once the biotin and streptavidin are bound it is unlikely that they will dissociate. This affinity is resistant to changes in temperature, pH, and salt concentration and is extremely specific. It is often thought of as a nearly covalent bond. These properties make biotinylation a useful tool for engineers who are developing new purification and detection methods. A commercially available biotinylation kit makes the process even easier.
The Enzyme Linked ImmunoSorbant Assay (ELISA) is the gold standard immunoassay for clinical diagnosis of disease. The basis of any immunoassay is the specific molecular recognition between antibody and antigen. This is something that the immune system does naturally. The production of monoclonal antibodies in a laboratory has become commonplace and standardized, which makes it possible to use monoclonal antibodies in immunoassays such as an IgG ELISA. The antibodies are easy to purchase from commercial vendors, and they come with quality control reports ensuring that they will recognize the target antigen.