Capture molecule

Capture molecule = probe] Gone-specific sequence,... 

Capture array involves the immobilization of non-protein molecules onto the surface which can interact with proteins in the solute phase. Generally, capture molecules may be broad capture agents based on chromatography type surface chemistries such as ion exchange, hydrophobic and metal affinity functionality, or they may be highly specific such as molecular imprinted polymers or oligonucleotide aptamers. 

Encapsulation The process of drying out a liposome and capturing molecules in the rehydration process. 

Equation (14.5) establishes the linear relationship between the RI sensitivity and the resonant mode s frequency shift for a given number of captured molecules at the OFRR surface. Also, note that the magnitude of the shift is directly proportional to the surface density and the excess polarizability of the bound molecules. Although (14.5) is developed for the OFRR, it is generally applicable to other types of ring resonator sensors, as is shown by Zhu, et al.27... 

A new suspension array concept based on sedimentation and microscopic imaging was introduced by Moser et al. [98], Magnetic microbeads settle to the bottom of a microplate well by magnetic forces and form randomly ordered arrays, which are examined by fluorescence microscopy and automated imaging analysis. Each bead carries specific capture molecules and can be identified by a defined luminescent code. 

Surface immobilization of the capture molecules follows standard procedures that are commonly practiced in many biosensor applications and some are discussed in the previous section. Layers of carboxymethyl dextran. Protein A or Protein G, streptavidin-coated surface, or EDC [N-ethyl-N-(diethylaminopropyl) carbidimide]/NHS (N-hydroxysuccmimide)-based amine coupling through amide bond are used for protein (antibody, receptor, etc.) cross-linking. 

Microarrays are solid phase-based assay systems consisting of an array of miniaturized test sites. This allows many tests to be performed in parallel. Planar protein microarray systems consist of capture molecules immobilized in rows and columns in microspots... 

In protein microarrays, capture molecules need to be immobilized in a functional state on a solid support. In principle, the format of the assay system does not limit the choice of appropriate surface chemistry. The same immobilization procedure can be applied for both planar and bead-based systems. Proteins can be immobilized on various surfaces (Fig. 1) (12). Two-dimensional polystyrene, polylysine, aminosilane, or aldehyde, epoxy- or thiol group-coated surfaces can be used to immobilize proteins via noncovalent or covalent attachment (13,14). Three-dimensional supports like nitrocellulose or hydrogel-coated surfaces enable the immobilization of the proteins in a network structure. Larger quantities of proteins can be immobilized and kept in a functional state. Affinity binding reagents such as protein A, G, and L can be used to immobilize antibodies (15), streptavidin is used for biotinylated proteins (16), chelate for His-tagged proteins (17, 18), anti-GST antibodies for GST fusion proteins (19), and oligonucleotides for cDNA or mRNA-protein hybrids (20). 

Arraying technologies involve contact and noncontact printing. Contact printing arrayers are equipped with sets of tiny pins that position subnanoliter quantities of capture molecules... 

Wei ST, Jakusch M, Mizaikoff B (2006) Capturing molecules with templated materials -analysis and rational design of molecularly imprinted polymers. Anal Chim Acta 578(1) ... 

After preparation (with beads of each red/orange ratio having been linked to capture molecules for specific targets), the beads can all be combined in a single tube. For the assay, a test solution is added to the mixed bead suspension. After incubation, centrifugation,... 

Beads Beads are particles (made, usually, of polystyrene) that can be used as stable and inert standards for flow cytometric analysis. Beads can be obtained conjugated to various fluorochromes in order to standardize fluorescence detection settings and optical alignment or to calibrate fluorescence scales. They can also be conjugated to antibodies in order to calibrate the scale in terms of number of binding sites. More recently, in multiplexed assays, beads with capture molecules have been used to determine the concentration of soluble analytes. 

There is no term in equation (21.3) for air flow. External air flow around organisms is sufficiently slow (subsonic) that it may usually be treated as incompressible (Vogel, 1994). This incompressibility means that the concentration of chemical stimulus molecules (n) will not be increased noticeably by the pressures that, develop adjacent to insect sensory hairs or antennae due to moving air (or moving antennae). The replacement of any captured molecules by the arrival of fresh odorant-laden air is the primary reason why air flow has such a dramatic effect on interception rate. One way of considering the influence of air flow is that at best the air flow could bring the interception rate closer to the limit predicted by equation (21.3). In order to discuss approaches more complex than that provided by equation (21.3), we have to consider the physical bases for molecular movements diffusion and convection. 

Koehl M. A. R. (2001) Fluid dynamics of animal appendages that capture molecules arthropod olfactory antennae. In Computational Modeling in Biological Fluid Dynamics, eds L. J. Fauci and S. Gueron, pp. 97-116. Springer Verlag, New York. 

Figure 14.14 Affinity contact printing (aCP)113 relies on inking the surface of a PDMS stamp with antigens as capture molecules, which allows subsequent binding of selected antibodies from a solution containing mixtures of proteins.

Reverse-phase protein arrays offer a robust new method of quantitatively assessing expression levels and the activation status of a panel of proteins. For this purpose, the lysate of protein(s) of interest is arrayed without selection via a capture molecule. This array can then be queried with an antibody or ligand probe, or an unknown biological component. Since an individual test sample is immobilized in each array spot, this array can be composed of a variety of different patient samples. Each array is incubated with one detection protein or antibody, and a single end point is measured across the arrayed cohort and can be directly compared across multiple samples. Replicates can be reproducibly printed at a given sitting, increasing quality control over a series of queried arrays (reviewed in [33]). 

Tiirola T, Jaakkola A, Bloigu A et al (2006) Novel enzyme immunoassay utilizing lipopo-lysaccharide-binding protein as a capture molecule for the measurement of chlamydial lipopolysaccharide in serum. Diagn Microbiol Infect Dis 54 7-12... 

Beyond these impacts, more advanced nanotechnology may allow active remediation of many environmental problems. For example, toxic wastes in contaminated aquifers may be neutralized by specially designed nano-robots (nanobots) that selectively capture undesirable molecules and then either sequester them for removal or break them down into harmless substances [114,118,119,124]. While nano-devices cannot, for example, render radioactive materials non-radioactive, they could capture molecules of radioactive waste and concentrate them into a form that would be easily removed [31-33]. 

Specificity An important criterion is also how specifically the capture molecule binds its interaction partner molecule. Nonspecific binding of matrix molecules to the sensing layer leads to false positive signals causing an error in the measurement values. Control experiments with compounds that show nonspecific adsorption, e.g., bovine serum albumin (BSA), are recommended. Blocking of the surface, meaning that a layer of e.g., BSA prevents the nonspecific adsorption of other matrix molecules and is displaced by the molecule interacting specifically, can also enhance the specificity in an assay. 

A further issue is the steric hindrance the interaction properties in a homogeneous assay are not directly transferable to the binding conditions at a surface/ interface. The binding site of an immobilized capture molecule is accessible only from one side. It must be exposed on the surface in an optimal manner. Likewise, the capturing partner, e.g., peptide or protein, should be oriented with its binding-active domain toward the sample solution. 

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