L-ethyl-3- 3-dimethylaminopropyl

Galactosylated chitosan prepared from lactobionic acid and chitosan with l-ethyl-3-(3-dimethylaminopropyl)-carbodiimideand N-hydroxysuccinimide was a good extracellular matrix for hepatocyte attachment [155] (Fig. 4). Furthermore, graft copolymers of galactosylated chitosan with poly(ethylene glycol) or poly(vinyl pyrrolidone) were useful for hepatocyte-targeting DNA carrier [156,157]. 

Purify conjugate by gel filtration, dialysis or ethanol precipitation EDC = l-ethyl-3-(3-dimethylaminopropyl)carbodiimide HQ. 

COOH groups of the PE (PAA or PGA) and the -NH2 moieties of the pre-loaded protein, using l-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC) as a catalyst [99]. Negligible enzyme desorption (<0.1 %) is observed from cross-linked lysozyme-loaded MS spheres after exposing the samples to an aqueous solution for 48 h, while about 25 % of the immobilized lysozyme is desorbed under the same conditions when the lysozyme is not cross-linked. 

The reactions involved in an EDC-mediated conjugation are discussed in Chapter 3, Section 1.1 (Note EDC is l-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride MW 191.7 and is sometimes referred to as EDAC). The carbodiimide first reacts with available carboxylic groups on either the carrier or hapten to form a highly reactive o-acylisourea intermediate. The activated carboxylic group then can react with a primary amine to form an amide bond, with release of the EDC mediator as a soluble isourea derivative. The reaction is quite efficient with no more than 2 hours required for it to go to completion and form a conjugated immunogen. 

Weigh out 1.25 mg of the carbodiimide EDC (l-ethyl-3-(3-dimethylaminopropyl)carbodii mide hydrochloride Thermo Fisher) into a microfuge tube. 

Figure 8 Chemiluminescent (A and B) and bioluminescent (C) detections for immobilized hybridizations of PCR product. Dg, digoxigenin Bt, biotin Ad, avidin. Procedure A [30] Biotin moiety is incorporated into PCR products during the amplification reaction, using one 5 -biotinylated primer. The product is hybridized with a Dg-labeled probe and is immobilized on streptavidin-coated magnetic beads. This capture reaction is carried out for 30 min at 37°C. A permanent magnet is used to sediment the beads during washing to remove unbound DNA. By incubation with the washed beads for 45 min at 37°C, anti-Dg antibody conjugated to HRP enzyme is bound to the Dg-labeled probe, and luminol reaction is performed for CL detection. Procedure B [31] Wells of apolystyrene microtiter plate are activated with l-ethyl-3-(3-dimethylaminopropyl)-carbodiimide, and then coated with a labeled cDNA probe complementary to an internal region of the target DNA.

Figure 1 Conjugation reactions for coupling peptides to the surface of preformed liposomes. Functionalized lipophilic anchors were incorporated into liposomes and reacted with the peptides in aqueous media. Reactive endgroup functions (A) maleimide (B) bromo- or iodoacetyl (C) 2-pyridyldithio (D) carboxylic acid (E) />-nitrophenyl carbonate and (F) hydrazide. Abbreviations EDC, l-ethyl-3-(3-dimethylaminopropyl)carbodiimide NHS, 7V-hydroxysuccinimide.

NPH HCl) with l-ethyl-3-(3-dimethylaminopropyl)-carbodiimide hydrochloride (EDC HCl) as a coupling agent [593,594], The advantage is that with hydrazines it is possible to carry out the derivatization in milder conditions. An efficient postcolumn derivatization is obtained using avidin or streptavidin. In fact, these two proteins react in a very specific way with biotin, therefore they are bound with a fluorescent marker, such as fluorescein 5-isothiocyanate (FITC) to obtain fluorescent derivatives. Some authors [595] report the use of MS or MS/MS for biotin detection, but this method seems to be less sensitive than FLD. 

The carbodiimide of choice used to couple cystamine to carboxylate- or phosphate-containing molecules is most often the water-soluble carbodiimide EDC (l-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride Chapter 3, Section 1.1). This reagent rapidly reacts with carboxylates or phosphates to form an active complex highly reactive toward primary amines. The reaction is efficient from pH 4.7 to 7.5, and a variety of buffers may be used, providing they do not contain competing groups. 

Add EDC (l-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride Pierce) to a final concentration of 2 mg/ml in the reaction solution. To aid in the addition of a small amount of EDC, a higher concentration stock solution may be prepared in water and an aliquot added to the reaction to give the proper concentration. Since EDC is labile in aqueous solutions, the stock solution must be made quickly and used immediately. 

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