PubMed Health⌕ Search

PubMed · 3072810

[Immunoenzyme analysis using paper disks].

Abstract

Filter paper discs have been used in the enzyme immunoassay (EIA) as solid phase instead of polystyrene plates. The use of paper discs has made it possible to achieve a multiple increase in the sensitivity of sandwich EIA, thus permitting the detection of Yersinia pestis capsular antigen at a concentration of 0.4 ng/ml. Paper discs can be used not only for the sorption of antigen and antibodies, but also for the affinity purification of preparations.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

M I Levi, V N Iagovkina. 1988. [Immunoenzyme analysis using paper disks].. https://pubmed.ncbi.nlm.nih.gov/3072810/

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

Three-dimensional porous nano-hydroxyapatite@gelatin composite as efficient adsorbent for uranyl ion removal from low-level radioactive wastewater.

The contamination of water resources by uranyl (UO22+) ions poses significant environmental and health risks, requiring the development of efficient and sustainable remediation strategies. Adsorption-based techniques have emerged as promising approaches in the field of UO22+ removal, but the design of cost-effective, high-capacity, and environmentally friendly adsorbents remains challenging. In this study, a three-dimensional porous nano-hydroxyapatite@gelatin (nHAP@Ge) composite was synthesized through glutaraldehyde cross-linking, combining the structural stability of Ge with the high uranium affinity of nHAP. The optimized nHAP@Ge, with a nHAP:Ge mass ratio of 1:0.5, exhibited exceptional UO22+ removal efficiency (97 %), along with high adsorption capacity (364.03 mg/g). Systematic characterizations using scanning electron microscopy (SEM), thermogravimetric analysis (TGA), Fourier transform infrared (FT-IR) spectroscopy, and X-ray photoelectron spectroscopy (XPS) methods revealed that the porous structure and surface functional groups (-OH, Ca2+, and PO43-) of the material synergistically contributed to binding UO22+ species. Furthermore, the incorporation of nHAP into the Ge framework resulted in enhanced thermal stability while significantly improving the UO22+ adsorption performance. This work presents a scalable, eco-friendly, and recyclable strategy for the effective treatment of uranium-contaminated water, with potential applications in nuclear wastewater treatment and environmental remediation.

Adsorption↗

Combined effects of anions on arsenic removal by iron hydroxides.

Batch experiments were conducted to investigate the combined effects of phosphate, silicate, and bicarbonate on the removal of arsenic from Bangladesh groundwater (BGW) and simulated groundwater by iron hydroxides. The apparent adsorption constants indicated that the affinity of the anions for iron hydroxide sites decreased in the following order arsenate>phosphate>arsenite>silicate>bicarbonate. Phosphate, silicate, and bicarbonate decreased the removal of As(III) even at relatively low concentrations and low surface site coverage. Phosphate (0-0.08 mM), silicate (0-0.8 mM), and bicarbonate (0-14 mM) in separate solutions had none to moderate effects on As(V) removal in a solution containing 6.7 mg/l Fe and 0.3 ppm As(V). In the presence of bicarbonate and silicate the adverse effect of phosphate on As(V) adsorption was magnified. The residual As(V) concentration after iron hydroxide treatment increased from less than 13 microg/l in separate bicarbonate (2.2 mM) and phosphate (0.062 mM) solutions to 110 microg/l in the solution containing both anions. The results suggested the combined effects of phosphate, silicate, and bicarbonate caused the high mobility of arsenic in Bangladesh water.

Adsorption↗

A kinetic model for enzyme interfacial activity and stability: pa-hydroxynitrile lyase at the diisopropyl ether/water interface.

A kinetic framework is developed to describe enzyme activity and stability in two-phase liquid-liquid systems. In particular, the model is applied to the enzymatic production of benzaldehyde from mandelonitrile by Prunus amygdalus hydroxynitrile lyase (pa-Hnl) adsorbed at the diisopropyl ether (DIPE)/aqueous buffer interface (pH = 5.5). We quantitatively describe our previously obtained experimental kinetic results (Hickel et al., 1999; 2001), and we successfully account for the aqueous-phase enzyme concentration dependence of product formation rates and the observed reaction rates at early times. Multilayer growth explains the early time reversibility of enzyme adsorption at the DIPE/buffer interface observed by both enzyme-activity and dynamic-interfacial-tension washout experiments that replace the aqueous enzyme solution with a buffer solution. The postulated explanation for the unusual stability of pa-Hnl adsorbed at the DIPE/buffer interface is attributed to a two-layer adsorption mechanism. In the first layer, slow conformational change from the native state leads to irreversible attachment and partial loss of catalytic activity. In the second layer, pa-Hnl is reversibly adsorbed without loss in catalytic activity. The measured catalytic activity is the combined effect of the deactivation kinetics of the first layer and of the adsorption kinetics of each layer. For the specific case of pa-Hnl adsorbed at the DIPE/buffer interface, this combined effect is nearly constant for several hours resulting in no apparent loss of catalytic activity. Our proposed kinetic model can be extended to other interfacially active enzymes and other organic solvents. Finally, we indicate how interfacial-tension lag times provide a powerful tool for rational solvent selection and enzyme engineering.

Adsorption↗