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Sandwich ELISA

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. This is different from direct and indirect ELISAs where the antigen is immobilized onto the surface.

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Biotinylated proteins and oligonucleotides

Biotinylation is the process of attaching a biotin tag to a molecule. The molecule can be a protein or an oligonucleotide. Biotinylated molecules are useful in many biological contexts, but are primarily used for capture or detection of target molecules. Biotinylated molecules are used in Western blotting, ELISA, flow cytometry, and other inventive detection methods.

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Gold nanoparticles applications

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.

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Molecularly imprinted polymers

The molecularly imprinted polymers (MIP) is a relatively new diagnostic and therapeutic tool. MIPs  are highly specific three dimensional polymer imprints of molecules. The power of this tool may not be immediately obvious, but it is indeed a very useful technology. The power of MIPs lies in their specificity of binding to target molecules. Before the invention of MIPs, the only way to achieve this type of specificity was through antibody-antigen binding, surface receptor-ligand interactions, or protein affinities such as streptavidin and biotin. The problem with all of these systems is that they need to already exist. But what about a target that doesn't have a known molecule with a natural affinity? Herein enters molecularly imprinted polymers. These polymers are crosslinked and formed around the target molecule. Once the polymerization process is complete, the target molecule template is destroyed. What remains is a three-dimensional polymer with binding sites in the exact physical and chemical configuration as the target molecule. These binding sites are specific with regard to hydrophobicity, hydrophilicity, chemical groups, hydrogen bonding, and charge. When these MIPs are added to solution they will bind the target molecule with exceptional specificity.

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Properties of nano gold

Nano gold is another name for gold nanoparticles. These nanoparticles are a fraction of the size of human hair and are less than 100 nm in diameter. Nano gold particles are so small that it they are generally found as a colloidal solution, which means that the gold nanoparticles are suspended in a liquid buffer. Therefore, nano gold, or gold nanoparticles are also called colloidal gold. Also, nano gold is generally found in a colloidal solution because gold nanoparticles are created by citrate synthesis. This process involves mixing solutions together to result in the precipitation of gold nanoparticles into solution.

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Pathogen detection using magnetic nanoparticles or molecularly imprinted polymers

Faster and more efficient methods of pathogen detection are in high demand. The traditional methods involve collection of patient blood or swab samples for multi-day cultures. These traditional methods are time-consuming and require full laboratories with skilled technicians and sterile equipment. As such, they are not ideal for low-income areas or for rapid pathogen detection. There is a need for rapid pathogen technology and point-of-care diagnostic tools. Magnetic nanoparticles and molecularly imprinted polymers are good candidates for improved pathogen detection systems.

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Sucrose gradient centrifugation to separate silver nanoparticles by size

As with any nanoparticle, the properties of silver nanoparticles are dependent on size. Many synthesis strategies produce nanoparticles with a wide size distribution. One way to separate these particles based on size is to use density gradient centrifugation. A sucrose gradient is an easy way to perform this separation because the sucrose gradient is simple to create using common laboratory equipment.

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Filter membrane

 Filtration is a common technique for mechanically separatinggases or liquids. A filter membrane serves as a barrier to enable ion exchange, removing macromolecules or bacteria from solution, separating colloids, or recovering gases. Some uses for filtration include producing clean drinking water, generating safe food products, and ensuring a clean environment. It is used for petro-chemical vapor recovery, oxygenation of blood in an artificial lung, and hemodialysis via an artificial kidney. Filter membranes are necessary for ion exchange in a fuel cell and for electrolysis. Filtration is also a key procedure in the laboratory to separate RNA, DNA, cells, proteins, and other molecules.

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Pharmaceutical validation

Pharmaceutical validation is important to the manufacturing process to ensure product consistency and safety. It involves regulation of all raw materials and production procedures as well as testing of final product. The general rule of thumb is to follow good manufacturing practice (GMP). This demands that all protocols be up to date and followed by trained personnel. It also requires that equipment be well-maintained and inspected. In the case of clean-room usage the clean room needs to be verified.

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Industrial uses of enzymes

Enzymes are used in the food, agricultural, cosmetic, and pharmaceutical industries to control and speed up reactions in order to quickly and accurately obtain a valuable final product. Enzymes are also increasingly being used in the production of biofuels and biopolymers. The enzymes can be harvested from microbial sources or can be made synthetically. Yeast and E. coli are commonly engineered to overexpress an enzyme of interest. This type of enzyme engineering is a powerful way to obtain large amounts of enzyme for biocatalysis in order to replace traditional chemical processes.

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