Albumin with glutaraldehyde

Protocol 1. Conjugation of a peptide to bovine serum albumin with glutaraldehyde... 

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. 

The preparation of microspheres can be accomplished by either of two methods thermal denaturation, in which the microspheres are heated to between 95 and 170°C, and chemical crosslinking with glutaraldehyde in a water-in-oil emulsion. Well-defined microspheres can be easily prepared using these methods in large batches which are usually physically and chemically stable. Newer preparation methods for the preparation of albumin microspheres have been described by several authors (84-88). 

Fig. 17. The water proton spin-lattice relaxation rates as a function of magnetic field strength reported as the proton Larmor frequency in aqueous 1.8 mM samples of bovine serum albumin. The lower data set was taken on the solution, the open circles taken after the sample had been cross-linked with glutaraldehyde to stop rotational motion (89).

The micro-hypoxanthine sensor was made by immobilizing xanthine oxidase with bovine serum albumin and glutaraldehyde on the micro-oxygen electrode (Fig. 3.18.D). The detection limit achieved was 6.7 pM and the sensitivity was ca. 10 times higher than that afforded by conventional hypo-xanthine sensors. 

Urea in kidney dialysate can be determined by immobilizing urease (via silylation or with glutaraldehyde as binder) on commercially available acid-base cellulose pads the process has to be modified slightly in order not to alter the dye contained in the pads [57]. The stopped-flow technique assures the required sensitivity for the enzymatic reaction, which takes 30-60 s. Synchronization of the peristaltic pumps PI and P2 in the valveless impulse-response flow injection manifold depicted in Fig. 5.19.B by means of a timer enables kinetic measurements [62]. Following a comprehensive study of the effect of hydrodynamic and (bio)chemical variables, the sensor was optimized for monitoring urea in real biological samples. A similar system was used for the determination of penicillin by penicillinase-catalysed hydrolysis. The enzyme was immobilized on acid-base cellulose strips via bovine serum albumin similarly as in enzyme electrodes [63], even though the above-described procedure would have been equally effective. 

Albumin nanoparticles can be prepared by controlled desolvation, pH-induced coacervation, and/or chemical cross-linking with glutaraldehyde. Briefly, the pH of an aqueous solution of albumin is raised to about 9.0 and nanoparticles are precipitated by adding a miscible cosolvent such as acetone [32], A study reports attempts to optimize the desolvation method to prepare albumin nanoparticles of a more controlled particle size and narrower particle size distribution [33],... 

Aqueous solutions of proteins such as albumin can be emulsified in an oil and induced to form microspheres, either by crosslinking the protein molecules with glutaraldehyde or other agents or by coagulating the protein by heating. Incorporation of a dmg within the initial protein solution results in dmg-laden microspheres which are biodegradable. The particle size of the microspheres (generally 0.2-300 jum diameter) is determined by the size distribution of the initial emulsion. 

A sensitivity of 74 mV/decade was obtained with this sensor. With HRP the sensor was stable for 7 days, and with Mo(IV) it was stable for 3 days. The response time was between 2 and 12 min, the measuring time between 35 and 70 min. An increase of the stability to 14 days by crosslinking with glutaraldehyde and bovine serum albumin (BSA) was accompanied by a sensitivity drop to 50% (43 mV/decade). 

Penicillinase cross-linked with bovine serum albumin using glutaraldehyde cast on a pH-sensitive field effect transistor Penicillin [34]... 

Glucose oxidase cross-linked with glutaraldehyde into bovine serum album bovine serum albumin membranes on carbon fiber electrodes Glucose [36]... 

In subsequent studies (64,65), various cholinesterases were tested as coatings, and were immobilized using different agents glutaraldehyde, bovine serum albumin, diazo coupling, and carbodiimide. Eel Cholinesterase, immobilized with glutaraldehyde exhibited the highest sensitivity for DIMP. 

M. Nakamura, S. Kiyohara, K. Saito, K. Sugita and T. Sugo, Chiral Separation of DL-Tryptophan Using Porous Membranes Containing Multilayered Bovine Serum Albumin Crosslinked with Glutaraldehyde, J. Chromatogr. A, 822 (1998) 53. 

Crude preparations of gangliosides have been treated with albumin via a carbodi-imide mediator. The reaction was stopped by precipitation with ammonium sulphate. Following resuspension of the precipitate, unsubstituted albumin was mixed with the albumin-ganglioside conjugate and the suspension treated with glutaraldehyde and then coated onto cellulose filters. These ganglioside affinity filters could be used for the identification of toxigenic strains of Clostridium botulinum types C and D. 

Paraformaldehyde-mediated reaction in the presence of bovine serum albumin with the surface of a Teflon membrane Glutaraldehyde cross-linking in the presence of ovalbumin onto mycelium pellets of Aspergillus species Periodate-oxidized enzyme treated with amino-organosylochrome... 

After the preparation of the microplatinum electrode in a Teflon casing, pladnization is performed by electrochemical reduction of hexachloroplatinate in the presence of lead acetate, following which enzyme incorporation is carried out. The electrode is immersed in an albumin solution and then treated with glutaraldehyde. 

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