Showing papers on "Glutaraldehyde published in 1975"

Construction and study of electrodes using crosslinked enzymes

Abstract: The construction of electrodes, the behavior of which could be accurately analyzed and optimized is described. Two methods were used to construct such enzyme electrodes. A direct binding method, where a cation electrode was dipped into a solution of enzyme, albumin, and glutaraldehyde: a thin layer of cross-linked protein coated the electrode bulb. A two-step method, where an active membrane was first made by cross-linking these proteins by glutaraldehyde on a glass plate, then fitting with a silicone membrane onto a gas electrode (O2 or CO2). Both methods were used to construct glucose and urease electrodes measuring either NH4+ ions or CO2. Glucose oxidase and L-amino acid oxidase-pO2 electrodes were also developed. The theoretical and experimental behavior of these enzymatic membrane electrodes were compared using the analysis of product concentrations resulting from the association of diffusion with enzyme reaction in the active layer, and the optimum operating conditions were determined.

Lactase and other enzymes bound to chitin with glutaraldehyde

Abstract: Acid tolerant lactase (I), α-chymotrypsin (II), and acid phosphatase (III) were immobilized on chitin with glutaraldehyde. Pretreatments of the chit in with acid, alkali, ammonia, and pronase were compared with respect to release of titratable amino groups and ability to retain lactase activity. Shrimp chitin appeared to be more sensitive to pretreatment conditions and so effort was concentrated on crab. An acid-alkali pretreatment was selected as most practical and economical, and the properties of enzymes fixed on crab chitin were studied intensively. The pH optima of the fixed enzymes were shifted about one pH unit; the shift for I was toward more acid pH, for II was toward alkaline pH, and for III was toward acid pH. The retained activity of immobilized I was approximately 60% that of the native enzyme. A column in continuous operation with I on chitin-glutaraldehyde gave an apparent activity half-life of 27 days.

The reactions of glutaraldehyde with nucleic acids.

Abstract: The kinetics of the reactions between glutaraldehyde, RNA and DNA have been investigated. At temperatures up to 64 degree C no reaction occurred between native DNA and glutaraldehyde. At temperatures above 75 degree C the reaction followed pseudofirst order kinetics, proceeding more quickly at higher temperatures. Reactions between RNA and glutaraldehyde were similar, except that they began above 45 degree C. These findings were corroborated by thermal transition profiles. There was little evidence for the formation of cross-links between nucleic acid molecules even at elevated temperatures.

Studies on the Synthetic Capacity and Antigenic Expression of Glutaraldehyde-Fixed Target Cells

Abstract: Mastocytoma cells (P815 of the DBA/2 strain) treated with increasing concentrations of glutaraldehyde were concurrently evaluated for their ability to incorporate exogeneous uridine, thymidine, and amino acids. The antigenic expression and membrane integrity of these treated cells were assayed by measuring their susceptibility to lysis by antibody and complement and by T-effector cells. The concentrations of glutarladehyde required to effect target cell antigen display were greater than those required to inhibit totally the cell's protein and nucleic acid synthetic processes. Thus, P815 cells treated with 0.15% glutaraldehyde for 10 sec were unable to incorporate either amino acids or nucleotides into macromolecules, but were readily lysed by effector T cell populations, and by alloantibody in the presence of complement. Target cells treated with glutaraldehyde concentrations in excess of 0.25% for 10 sec were resistant to both forms of immune lysis. In keeping with these observations, monolayers of P815 cells treated for 10 sec with 0.15% glutaraldehyde, were capable of specifically depleting T-effector cells from a cytolytically-active spleen cell population. After treatment with higher concentrations of glutaraldehyde (0.3%), however, the monolayers lost their capacity to adsorb effector cells. Although P815 cells treated with glutaraldehyde continued to exhibit H-2d alloantigen, neither these cells nor glutaraldehyde-treated DBA/2 spleen cells induced significant blastogenesis or stimulated the production of cytolytically active effector cells in mixed leukocyte cultures.

Enzymes immobilized on alumina and stainless steel supports

Abstract: Enzymes can be sorbed on inorganic carriers followed by crosslinking with glutaraldehyde. In some cases superior results are obtained when the support is precoated with a porous layer of titanium oxide. Immobilized lactase prepared in this way retains essentially all its activity when stored under water at 23°C for long periods of time and loses activity only slowly while treating cheese whey at 55°C over the course of several weeks contact time. Furthermore, catalyst activity is unaffected by frequent sanitization. Optimum pH for these immobilized-lactase catalysts (enzyme produced from A. niger) is about 3.0 and optimum temperature is about 60°C. Amyloglucosidase catalase, L-asparaginase, and trypsin have also been immobilized by these techniques.

The binding of cationized ferritin at the surfaces of ehrlich ascites tumor cells: the effect of pH and glutaraldehyde fixation.

Abstract: The densities of cationized ferritin (CF) particles binding to the surfaces of cultured Ehrlich ascites tumor cells were determined at pH 74, where the ferritin stain was applied either prior to or following glutaraldehyde fixation The densities were also determined with CF adjusted to pH 19 and applied after fixation For all fixed samples there was a higher density of particles bound to microvilli than to the spaces between them Treatment with neuraminidase removed more particles from microvilli than from the intermicrovillus spaces, but did not reduce the levels of binding to the same value When cationized ferritin is applied prior to fixation, an aggregation of the CF particles at the cell surface was observed, with the internalization of some clusters This effect was independent of neuraminidase treatment

Inactivation of enterovirus by glutaraldehyde.

Abstract: A study on the rate of inactivation by glutaraldehyde of coxsackievirus was conducted using different concentrations, temperatures, and pH values. It was found, that 2% glutaraldehyde at pH 7.4 and 25 C, as recommended for a sporicide, reduced the titer of infectious virus by 2 log10 U in 1 min or less. The reduction was not negatively affected by high concentrations of organic matter (serum and animal spillings) in the reaction mixtures.

Lipid staining for the electron microscope: a new method

Abstract: Tissues fixed in osmium tetroxide or in combined osmium and glutaraldehyde (Hinde), embedded in Spurr's medium, cut at 0-5-I mum and mounted in Farrants' gum medium containing ethyl gallate, show good staining of lipid-contaning structures (droplets of triglyceride, membranes, mitochondria, etc.) in the light microscope. Such preparations show moderate contrast in the electron microscope without further staining. But a specific increase in contrast in lipid-rich structures is obtained by partition of the tissues, before embedding, in 70% ethanol saturated with the monoterpene hydrocarbon myrcene, with or without the addition of 0-I % ethyl gallate, followed by osmium tetroxide. This method will visualize both saturated and unsaturated lipids, including waxes.

Soil sterilization effects on in situ indigenous microbial cells in soil.

Abstract: Soil was sterilized by various procedures, and then the resident microorganisms were physically separated and concentrated from the soil for viewing by transmission electron microscopy as thin sections and frozen-etched preparations. Remaining cell viability in the soil was tested by conventional plating before and after enrichment culture. The soil proved to be sterile after treatment with 60Co radiation, prolonged autoclaving, prolonged dry heat application at 200C, or glutaraldehyde (if followed by subsequent mild heating), and could be considered sterile after OsO4 treatment. Treatment with glutaraldehyde alone, or 160C dry heat for 3 h, did not sterilize the soil. Cellular fine structure was altered or destroyed by the heat treatments, but was not affected to any extent by any of the other treatments including glutaraldehyde followed by mild heating. These findings are considered in relation to the residual biological information observable by electron microscopy in soil samples which have been steri...

Changes of particle frequency in freeze‐etched erythrocyte membranes after fixation

Abstract: The frequency of particles on the membrane fracture faces of freeze-etched human erythrocytes was measured, and the effect of fixation procedures on the particle frequencies was studied. Fresh blood, buffer washed cells and cells fixed in one of the following ways were examined: glutaraldehyde, glutaraldehyde followed by osmium tetroxide, osmium tetroxide alone. Quantitative analyses showed that some treatments produced a significant reduction in the number of particles on the fracture faces as compared with the fresh cells. After both osmium tetroxide fixations, the loss of particles was greater from the outer fracture face (OFF) than the inner fracture face (IFF), whilst after the other treatments approximately the same number of particles were lost from both fracture faces. The results are discussed with respect to some current concepts of the molecular architecture of the erythrocyte membrane and the action of fixatives. The reduction of particle frequencies is thought to be due to both leaching of membrane proteins, and deviations of the usual fracture plane within the membrane. Glutaraldehyde alone was shown to have less effect on particle frequency than the other fixatives and it is therefore a suitable fixative for the preparation of freeze-etch specimens.

Glutaraldehyde: cross-reactions to formaldehyde?

Abstract: reacted to nickel sulphate and cobalt chloride. She was also intracutaneously tested with atopic allergens and reacted to extract of human dander. Both results could offer some explanation for the itchy exacerbations. After avoidance of nickel and cobalt contact, as far as possible, there was much improvement. A course of Vitamin B12 injections was prescribed (Polgar & Spat 1959). In the evening of the day on which she had her third injection of 250 p,g she had a sudden bullous flare on her hands, and less on her feet. This healed in a couple of days without specific treatment; only her previously prescribed corticosteroid cream and ointment were continued. The recommended daily intake of Vitamin B12 is 2p,g. Rich sources containing more than 10 p,g/100 gr wetweight are organ meats, clams and oysters. The cobalt binding in the porphyrin-like structure is covalent rather than ionic. Dalderup (1968-1971) reports cases of urticaria and anaphylactic reaction. Both might have been due to impurities or preservatives. He also reports publications pointing to acne as a side effect. Hpvding (1968) saw an anaphylactic reaction after an injection of Vitamin B12 in a patient reacting to tests with the purified material, but not reacting to cobalt chloride. My patient was prick tested with one drop of a cyanocobalamine (Vitamin Bt2) solution of 250 p,g/ml and patch-tested with such a solution (concentrated by evaporation of the solvent to such a degree that an amount of 0.1 mg of Vitamin B12 must have been present on the Whatman paper square slightly wetted with the solvent used in the vial). Both tests remained negative. I did not dare to allow the patient to swallow a small amount of cobalt salt (as was done for instance with dichromate, and azo dyes) because the patient had psoriasis. If the patient had reacted to such an intake this could have supported the idea that Vitamin B12 in the body could release cobalt. Hjorth (1958) described a girl with an occupational contact dermatitis to Vitamin Bt, with a relapse after ingestion of that vitamin and with a cross-sensitization to Co carboxylase.

Killing bacterial spores with glutaraldehyde sporicidal compositions

Abstract: This invention relates to new and improved means for killing spores on instruments and the like utilizing the combination of glutaraldehyde and a detergent selected from the group consisting of nonionic, anionic and ampholytic surface active agents. The sporicidal kill activity of glutaraldehyde is enhanced by said detergents.

Chemical composition and biophysical properties of porcine cardiovascular tissues.

Abstract: Collagen from the cardiovascular system is extremely resistant to proteolytic digestion, in contrast with the proteoglycans of these connective tissues. In particular this is true for the heart valves, which contain the largest proportion of collagen. The tensile strength of aortic tissue incubated at 37°C declines rapidly unless fixed with aldehydes. Stabilized glutaraldehyde gives rise to the most stable form of cross-link and renders the tissue structurally intact after more than 4 years of incubation at 37°C in physiological solution. Formaldehyde, on the other hand, gives rise to transcient crosslinks.These findings are of significance in attempting to understand the behavior of homo- and heterograft tissues implanted for prosthetic purposes, since their functional integrity depends on the maintenance of a structurally adequate connective tissue network.

Staining of the elastic fibers in insect connective tissue after tannic acid/glutaraldehyde fixation

Abstract: Locust neural lamella and Calpodes connective tissue fixed in glutaraldehyde have a fibrous component which stains after reaction with DAB and osmication and after staining sections with PTA. The fibers also stain when fixed in glutaraldehyde with tannic acid followed by osmication and section staining with lead citrate.

Electrochemical evaluation of glucose oxidase immobilized by different methods

Abstract: Glucose oxidase electrodes were constructed on a platinum screen using polyacrylamide gel, glutaraldehyde crosslinking, and glutaraldehyde crosslinking with +0.04 volts dc on the platinum screen as the methods of enzyme immobilization. The electrodes were evaluated in an electrochemical cell for the oxidation of glucose at the enzyme electrode and the reduction of oxygen at a platinum auxiliary electrode, using constant current voltametry or under external load operation. The method of immobilization affected the extrapolated opencircuit potential as well as the half-cell potential and the steady current under external load operation. The charged glutaraldehyde electrode gave the best current performance; however, the small output (microamps) indicated that major problems in electron transfer from an enzyme catalyst to an external circuit must be resolved before such electrodes can be used in practical application.

The Feulgen Reaction after Glutaraldehyde Fixation

Abstract: A technique is described for performing the Feulgen reaction for DNA on cells and tissues fixed in glutaraldehyde. Blockade free aldehydes by reducing them with fresh 0.5% NaBH4 in 1% NaH2PO4 for 1 hr at room temperature, then rinse in water. Follow by a Feulgen reaction (hydrolysis at room temperature in 6 N HCI for 20 min, Schiff's reagent for 60 min.). Controls assure the completeness and irreversibility of the borohydride blockade. Cytophotometry shows that the DNA content per nucleus is unaffected by the blockade procedure.

Effect of glutaraldehyde and lead on the activity of hepatic glucose-6-phosphatase. A biochemical and cytochemical study.

Abstract: The sensitivity of mouse liver glucose-6-phosphatase activity towards glutaraldehyde fixation has been analysed by biochemical and cytochemical means. The degree of enzymatic inhibition and various enzymatic properties have been studied. Several differences have been observed in the Km determination, the sensitivity to pH 5 and the activity related to pH between fixed and unfixed enzymes. The role of Pb++ ions in the cytochemical media has also been estimated. It is concluded that several enzymatic differences appear between fixed and unfixed enzymes and that the inhibition by Pb ions is dependent on the buffer and on the amount of substrate used.

Means for killing bacterial spores with glutaraldehyde sporicidal compositions

Abstract: This invention relates to new and improved means for killing spores on instruments and the like utilizing the combination of glutaraldehyde and a monoaldehyde, such as, for example, formaldehyde. The sporicidal kill activity of the composition is more rapid than previously possible, and more effective than the use of either glutaraldehyde or monoaldehyde alone.

The interaction of glutaraldehyde with poly(α,L-lysine), n-butylamine, and collagen. II. Hydrodynamic, electron microscopic, and optical investigations on the reaction products

Abstract: Interactions of glutaraldehyde with either n-butylamine, poly(α,L-lysine), or collagen resulted in a fast release of protons in dilute aqueous solutions at various pH values, followed by much slower changes. The latter reactions, which extended over hours and days, were followed spectrophotometrically and revealed the formation of distinct absorption bands in the visible and near-ultraviolet regions in all the above systems. The visible-range bands disappeared upon treatment with sodium borohydride. A qualitative relationship between oxygen uptake by the system n-butylamine–glutaraldehyde and the slow formation of colored products has been established, while the chemical nature of the reaction products has not been determined. Sedimentation velocity, viscosity, and optical rotation measurements on the products of interaction between poly(L-lysine) and glutaraldehyde in aqueous solution indicated large conformational changes in the polyamino acid present in excess (in residues) over the dialdehyde. In particular, the intrinsic viscosity dropped considerably after interaction, indicating intramolecular crosslinking. At molar ratios of 1:1 between polylsine residues and aldehyde groups, intermolecular crosslinking of polylysine was obtained at pH 8.6. Electron microscopic examinations of collagen samples treated by glutaraldehyde at various pH values indicated changes from unordered to more ordered structures upon treatment with glutaraldehyde, in particular at pH 10. The present structural and optical investigations are considered to be relevant to tanning processes of hides and to fixation procedures.

Observation of the secretion on the surface of the bronchioles with the scanning electron microscope.

Abstract: The secretion covering the surface of the bronchioles can be demonstrated with the scanning electron microscope if fixative is introduced into the pulmonary artery or directly into the lung rather than through the trachea. Buffered glutaraldehyde, ethanol, or an ethanol-ether mixture can be used as a fixative. With this method of preparation the surface secretion appears as a smooth coating covering the cilia and cells. The secretion is insoluble in ethanol ether or chloroform methanol, suggesting that there is little lipid contained in it. Reasons are cited for believing that the major component of the secretion is a protein that arises from the Clara cell.