Chemical modification procedure

Brockman JM, Fmtos AG, Com RM (1999) A multistep chemical modification procedure to create DNA arrays on gold surfaces for the study of protein-DNA interactions with surface plasmon resonance imaging. J Am Chem Soc 121 8044-8051... 

The following sections describe the major enzymatic and chemical modification procedures used to label nucleic acids and oligonucleotides. 

As already pointed out in our previous papers [48-50], the high stability is probably the result of the newly developed chemical modification procedure which may lead to a stronger adsorption of the PB particles on the electrode surface. In contrast to the PB layer obtained with the more commonly used electrochemical procedures, these modified electrodes are in fact more stable at basic pH and their continuous use is possible with a minimal loss of activity after several hours. Moreover, with respect to the electrochemical procedure, our chemical deposition is much more suitable for mass production since no electrochemical steps are required and a highly automated process could be adopted (see Procedure 17 in CD accompanying this book). 

In the selection of a chemical modification procedure, two criteria have to be considered. 

There are several critical issues to consider in this research area. The kenaf fiber must not be degraded by the chemical modification procedures. To maintain the strength of the kenaf fiber, depolymerization or degradation of the cellulose must be avoided. 

Further studies of the n-heptyl viologen reaction on modified surfaces are reported elsewhere (25). It is clear that the interaction of ion-beams or plasmas with the electrode surface can be a powerful modification tool, complementary to chemical modification procedures for application to either photoelectrochemical or electrochromic reactions. 

The mediators are bound to amino acids near the prosthetic group. For fixation of the relays the protein has to be unfolded and renatured after the chemical modification procedure. The small distance between the bound mediator molecules (maximum 1 nm) provides a very fast tunneling process. Enzyme electrodes employing glucose oxidase or lactate oxidase modified in this way operate like mediator-modified electrodes, without reagent addition. Owing to their favorable structure, such sensors respond to the analyte in less than... 

M.W. Pennington, Site-specific chemical modification procedures, in M. W. Pennington, and B.M. Dunn, eds.. Methods in Molecular Biology, Peptide Synthesis Protocols, Humana... 

To elucidate the basic design parameteis for superoleophobicity, Zhao et al. [88] launched a systematic investigation using model pillar array surface with well-defined texture and geometiy. Figure 4.25 summarizes the surface texturing and chemical modification procedure for the fabrication of flie model textured surface. Details of the fabrication processes have been published elsewhere [88],... 

The success of dibekacin prompted worldwide attention to the removal of selected OH groups in aminoglycoside antibiotics susceptible to modification by resistant bacteria, and the chemical deoxygenation procedure of D. H. R. Barton was found particularly useful. 

Owing to multi-functionahty, physical properties such as solubihty and the glass transition temperature and chemical functionahty the hyperbranched (meth) acrylates can be controlled by the chemical modification of the functional groups. The modifications of the chain architecture and chemical structure by SCV(C)P of inimers and functional monomers, which may lead to a facile, one-pot synthesis of novel functionahzed hyperbranched polymers, is another attractive feature of the process. The procedure can be regarded as a convenient approach toward the preparation of the chemically sensitive interfaces. 

The synthetic procedure used for the chemical modification of PPO involved in the first step the radical bromination of PPO methyl groups to provide a polymer containing bromobenzyl groups. The bromobenzyl groups were then esterified under phase-transfer-catalyzed (PTC) reaction conditions with potassium 4-(4-oxybiphenyl)butyrate (Ph3C00K, Ph3C00-PP0), potassium... 

GC-C-IRMS instrumentation enables the compound-specific isotope analysis of individual organic compounds, for example, n-alkanes, fatty acids, sterols and amino acids, extracted and purified from bulk organic materials. The principle caveat of compound-specific work is the requirement for chemical modification, or derivatisation, of compounds containing polar functional groups primarily to enhance their volatility prior to introduction to the GC-C-IRMS instrument. Figure 14.7 summarises the most commonly employed procedures for derivatisation of polar, nonvolatile compounds for compound-specific stable isotope analysis using GC-C-IRMS. 

The chemical adjustment of charge density is another potentially rewarding technique. It does, however, require either the synthesis of new polymers or the chemical modification of preformed polymers (e.g., supersulfation of hyaluronic acid [16]). This procedure has not been evaluated in our screening. 

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