A novel approach to probe viscoelastic properties of cells based on double trap optical tweezers is reported. Frequency dependence of the tangent of phase difference in the movement of the opposite erythrocyte edges while one of the edges is forced to oscillate by optical tweezers appeared to be highly dependent on the rigidity of the cellular membrane. Effective viscoelastic parameters charact...

Glutaraldehyde is well known for its ability to react with proteins and to produce insoluble cross-linked aggregates. In contrast with this situation, conditions are described here which yield covalently linked soluble protein oligomers. The procedure is applicable to a wide range of proteins, and by slight variation in the reaction conditions, soluble polymers in the molecular weight range 3x1...

The structure and state of amyloid-β peptide (Aβ) oligomers often need to be checked by reliable experimental methods. Electrophoresis is a commonly applied measurement method. However, due to the presence of detergents, oligomers are easily broken during electrophoresis, which makes it very hard to accurately assess Aβ aggregate states. In the current study, bis(sulfosuccinimidyl) suberate (BS...

In this study the immobilization of lipase in matrices produced with gelatin with different Bloom values and with the addition of plastifiers was investigated to evaluate the influence of the Bloom value, as well as the capacity of the plastifiers to maintain the enzyme immobilized and the immobilization yield. The results indicated the need for crosslinking of the matrices with glutaraldehyde ...

A possibility of the creation of potentiometric biosensor by adsorption of enzyme urease on zeolite was investigated. Several variants of zeolites (nano beta, calcinated nano beta, silicalite, and nano L) were chosen for experiments. The surface of pH-sensitive field-effect transistors was modified with particles of zeolites, and then the enzyme was adsorbed. As a control, we used the method of...

The effectiveness of glutaraldehyde (GTA), a very common biocide for controlling biofilms formed by Pseudomonas fluorescens on stainless steel slides, in laminar and turbulent flow, was investigated. Tests were performed using a concentration of biocide of 200 mg L(-1) and a range of exposure times. The GTA action was assessed by means of activity tests and dry weight of the biofilms. The physi...

OBJECTIVES To estimate the social costs of occupational asthma in the UK. METHODS A desk-top approach using cost-of-illness methodology was employed, defining direct and indirect lifetime costs for six scenarios: a male and a female worker each exposed to isocyanates, latex and biocides (eg, glutaraldehyde) or flour. The numbers of new cases annually in each industry were estimated from Surve...

A passive microcapsule agglutination test for the diagnosis of leptospirosis was developed by utilizing chemically stable microcapsules instead of sheep erythrocytes. In the test, sonically disrupted antigens of leptospira were sensitized to microcapsules treated with glutaraldehyde. Compared with the microscopic agglutination test, the passive microcapsule agglutination test showed a relativel...

An indirect hemagglutination test for the diagnosis of leptospirosis is described; the test uses a soluble antigen from serotype patoc to sensitize sheep erythrocytes which are then fixed with glutaraldehyde. Evaluation of this procedure indicates that it is more reliable than the conventional macroscopic agglutination test and, in contrast with both microscopic and macroscopic agglutination te...

Recent publications on commercial porcine bioprosthetic cardiac valves have stated that the endothelium disappears during the glutaraldehyde processing and that in many cases histological evidence of early tissue deterioration was found. Our experiences have shown that porcine aortic valves can be processed in glutaraldehyde without loss of the integrity of the endothelium and with the developm...