Biomolecules, small, detection

In the field of responsive agents, enzyme targeting has specific advantages. A small concentration of the enzyme can convert a relatively high amount of the probe in multiple catalytic cycles which considerably decreases the detection limit for the enzyme as compared to other biomolecules. Moreover, enzymatic reactions are usually highly specific therefore, the observed change... 

Conventional evanescent sensing works exceedingly well for relatively small biomolecules such as proteins and DNA molecules whose size is much smaller than the decay length. However, it becomes less sensitive when detecting biospecies, such as cells, with dimensions over 1 pm. In Chap. 15, deep-probe waveguide sensors are developed to overcome this limitation, which have a decay length comparable to the size of the biospecies of interest. 

A RAM column functions through a size exclusion mechanism. Large biomolecules such as proteins are restricted from the adsorptive surfaces inside silica particles. Small analyte molecules are able to penetrate into the inner surfaces of the particles. As a result, protein molecules pass through the column rapidly and analytes of interest are retained on the adsorptive sites. Depending on the application, the analyte molecules are directed to MS for detection or transferred onto an analytical column for separation prior to MS detection. Detailed applications are discussed in a recent review.8... 

The Detection of Small Biomolecules Dairy Products in the Archaeological Record... 

Inner slip, between the solid wall and an adsorbed film, will also influence the surface-liquid boundary conditions and have important effects on stress propagation from the liquid to the solid substrate. Linked to this concept, especially on a biomolecular level, is the concept of stochastic coupling. At the molecular level, small fluctuations about the ensemble average could affect the interfacial dynamics and lead to large shifts in the detectable boundary condition. One of our main interests in this area is to study the relaxation time of interfacial bonds using slip models. Stochastic boundary conditions could also prove to be all but necessary in modeling the behavior and interactions of biomolecules at surfaces, especially with the proliferation of microfluidic chemical devices and the importance of studying small scales. 

There is often a need for a visualization procedure that is specific for a certain biomolecule, for example, an enzyme. If the enzyme remains in an active form while in the gel, any substrate that produces a colored product could be used to locate the enzyme on the gel. Although it is less desirable for detection, the electrophoresis support medium may be cut into small segments and each part extracted with buffer and analyzed for the presence of the desired component. 

Because of concerns about the safety of radioisotope use, researchers are developing fluorescent and chemiluminescent methods for detection of small amounts of biomolecules on gels. One attractive approach is to label biomolecules before analysis with the coenzyme biotin. Biotin forms a strong complex with enzyme-linked streptavidin. Some dynamic property of the enzyme is then measured to locate the biotin-labeled biomolecule on the gel. These new methods approach the sensitivity of methods involving radiolabeled molecules, and rapid advances are being made. 

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