Glutaraldehyde applications

Albumin cross-linked with glutaraldehyde is sold at a cost of approximately 90 per ml and comes in a 5 ml kit. The adhesive can be stored at room temperature and preparation time including assembly of the applicator gun can be completed in several minutes. 

Combined Chlorine-Aldehyde Treatment A combined chlorine-aldehyde treatment that has two stages, that is, chlorination and subsequent biocide application, has been suggested. Short-residence-time shock doses of glutaraldehyde have been applied after chlorination [1180]. It has been established that a primary chlorination in overall bacterial control is useful. 

Despite the obvious disadvantages of glutaraldehyde-mediated conjugation, the crosslinker continues to be used to form enzyme-antibody complexes and in other applications. Many diagnostic tests still utilize antibody-enzyme conjugates prepared through glutaraldehyde... 

Autofluorescence of cells often complicates the studies with fluorescence microscopy (especially the application of green fluorescent substances). There are different reasons for the occurrence of this phenomenon (157) (i) the fluorescent pigment lipofuscin, which settles with rising age in the cytoplasm of cells (ii) cell culture medium, which often contains phenol red that increases autofluorescence (iii) endogen substances such as flavin coenzymes [flavin-adenine dinucleotide (FDA), flavin mononucleotide (FMN) absorp-tion/emission 450/515nm], pyridine nucleotides [reduced nicotinamide adenine dinucleotide (NADH) absorption/emission 340/460nm] or porphyrine (iv) substances taken up by cells (as mentioned above filipin) and (v) preparation of the cells fixation with glutaraldehyde increases autofluorescence. 

Fixation in glutaraldehyde prodnces better morphology, but induces a great deal of autofluorescence, and limits cytoplasmic and nnclear permeability. A protocol utilizing glutaraldehyde followed by borohydride treatment has been previously described that is applicable also for electron microscopy of cultnred cells (4). Some areas of the cell are relatively impermeable with this approach, bnt this is an excellent choice of fixative protocol for microtnbnle morphology. 

In view of the ability of nitromethane to undergo a cyclizing bis-aminoalkylation when reacted with dialdehydes in the presence of amines 80,61) its application to other nitromethylene compounds seems an obvious extension. This reaction has already been verified when glutar-aldehyde is allowed to react with nitromethane and benzylamine in a 1 2 4 molar ratio in water, lr-methyl-l-nitro-2c,6c-bis-benzylamino-cyclohexane (110) is obtained in 56% yield 2) xhe same product is isolated in even higher yield (83%) on treatment of the nitroethane-glutaraldehyde cyclization product (6) with benzylamine However, further work is required to evaluate the preparative utility of this reaction principle for the synthesis of C-methyl branched triaminosugars. 

Schmid et al. used the same principle to develop sensors to be incorporated into FI systems for the determination of ascorbic acid in fruit juices [38] and that of lactic acid in dairy products [39]. The membrane used in both applications consisted of decacyclene dissolved in silicone rubber that was treated similarly as the membrane in glucose sensors (Fig. 3.4.B). The oxygen optrode was coated with a sheet of carbon black as optical insulation in order to protect it from ambient light or intrinsic sample fluorescence. Ascorbic acid oxidase or lactic acid oxidase was immobilized by adsorbing it onto carbon black and cross-linking it with glutaraldehyde. The FI system automatically buffered and diluted the food samples, thereby protecting the biosensor from a low pH and interferents. 

Some common compounds which are approved for various fuel-water biocide applications include glutaraldehyde, methylene bis-thiocyanate and 2-methyl-4-... 

Immobilization. The fixing property of PEIs has previously been discussed. Another application of this property is enzyme immobilization (419). Enzymes can be bound by reactive compounds, eg, isothiocyanate (420) to the PEI skeleton, or immobilized on solid supports, eg, cotton by adhesion with the aid of PEIs. In every case, fixing considerably simplifies the performance of enzyme-catalyzed reactions, thus facilitating preparative work. This technique has been applied to glutaraldehyde-sensitive enzymes (421), a-glucose transferase (422), and pectin lyase, pectin esterase, and endopolygalacturonase (423). 

Because enzymes can be intracellulady associated with cell membranes, whole microbial cells, viable or nonviable, can be used to exploit the activity of one or more types of enzyme and cofactor regeneration, eg, alcohol production from sugar with yeast cells. Viable cells may be further stabilized by entrapment in aqueous gel beads or attached to the surface of spherical particles. Otherwise cells are usually homogenized and cross-linked with glutaraldehyde [111-30-8] to form an insoluble yet penetrable matrix. This is the method upon which the principal industrial applications of immobilized enzymes is based. 

Hayat, M. A. 1986. Glutaraldehyde Role in electron microscopy. Micron Microsc. Acta 27 115-135. Hayat, M. A. (ed.). 1989-1991. Colloidal Gold Principles, Methods, and Applications, Vols. 1-3. Academic Press, San Diego. 

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