Magnetic latex

Keywords Core-sheU morphology Dispersion polymerization - Emulsion polymerization Ferrofluids Hybrid latex Magnetic latexes - Magnetic nanoparticles... 

Carty, P. White, S. Price, D. Lu, L. (1999) Smoke suppression in plasticised chlorinated poly(vinyl) chloride (CPVC). Polymer Degradation Stability 63 465-468 Caruso, F. Susha, A.S. Giersig, M. Moh-wald, H. (1999) Magnetic core-shell particles Preparation of magnetite multilayers in polymer latex microspheres. Adv. Mater. 11 950-952... 

Heat-sealable plastic bags and apparatus Heating blocks, thermostat-controlled metal heating block that holds test tubes and/or microcentrifuge tubes Hoods, chemical and microbiological Hot plates, with or without magnetic stirrer Gloves, plastic and latex, disposable and asbestos... 

Adsorb the antibody to a solid support such as the surface of a plastic tube, multiwell plate, latex particle, magnetic particle, nylon, nitrocellulose, or glass fiber filter. 

The latexes were cleaned by ion exchange and serum replacement, and the number and type of surface groups were determined by conductometric titration. The molecular weight distributions of the polymers were determined by gel permeation chromatography. The stability of the latexes to added electrolyte was determined by spectrophotometry. The compositional distribution was determined by dynamic mechanical spectroscopy (Rheovibron) and differential scanning calorimetry, and the sequence distribution by C13 nuclear magnetic resonance. 

Many materials exist that have dimensions in the range of 1 rnn to several micrometers. Recall that colloidal particles (e.g., latex particles from emulsion polymerization, colloidal silica or alumina, etc.) fall in the range from about 10 nm to 1000 nm (1 jxm). A few examples of nanoparticles that are designed with more specific structures or geometries include carbon nanotubes, metal clusters, nanoscale magnetic crystals, and semiconducting ... 

Emulsion polymerization was successfully employed for the preparation of nano-scale MIPs by synthesizing core-shell latexes with an imprinted shell. The use of a template with surfactant properties led to enhanced surface imprinting. Magnetic cores were synthesized to render MIPs which could be manipulated by magnetic fields in suspension, thereby facilitating the separation of the colloidal solid phase from the suspending solution. 

Numerous studies on bead bio chips were therefore based on magnetic [16,17], glass or silica [18-20], and polystyrene beads [21]. The DNA immobilization chemistry of those beads could be very different, from the classical avidin/biotin affinity reaction [17,22] (Fig. 2B) to the disulfide bridging onto thiol modified silica [19] (Fig. 5A), the thiocyanate reaction onto amino-terminated latex beads [21] (Fig. 5B), and finally the hybridization-based immobilization of poly(A)-tagged probes onto poly(T)-bearing magnetic beads [16] (Fig. 5C). 

As a flnal example, it should be pointed out that it is also possible to circumvent the need of immobilization of the biorecognition element in the microchannel system. Instead, it can be immobilized on superparamagnetic beads, silica beads, latex particles, etc. [79-81]. These beads are applied together with the sample into the microchannel system and can be collected on or near the transducer via magnetic or membrane separation. 

The simplest way of fraction separation, however, is when one of the immunoreactants (i.e., either the antigen or the antibody) is immobilized on a solid phase, i.e., immunoreagent modified solid-phase separations, such as plastic tubes, microtitre plate, latex-, glass- or magnetic beads, dipsticks or nitrocellulose membranes [121]. The efl ciency of separation is determined by the nature of the solid surface. Unspecific binding of the label to the solid phase can occur, especially when the latter has hydrophobic properties [96]. The adsorption of the antibody to the solid surface causes its partial inactivation, which can explain some unexpected effects when comparing the same antibody used in liquid and solid-phase systems (see also Section 9.3.4.4). 

To determine the nature of the silicon moieties in a polymer, clearly the easiest method would be a technique that provides a direct observation of the silicon atom and meaningful, interpretable information on the atom. Nuclear magnetic resonance spectroscopy tuned to the Si isotope ( Si NMR) is a tool of this nature it can directly probe the state of the silicon atom, and with it one can often readily determine the extent to which Si-O-Si crosslinks (fi-om silanol condensation), have formed. One can observe spectra of silicon-containing compounds either dissolved in a solvent or in the solid state. Liquid-state Si NMR, while the most sensitive, cannot be used quantitatively on heterogeneous systems such a latex formulations. Therefore, one must separate the liquid and solid portions of the latex (without heat, which would promote hydrolysis and condensation) and use the solid residue for the Si NMR experiments. 

As E. coli 0157 H7 is the most implicated STEC serotype in human cases, numerous immuno-based methods for the detection of this specific serotype have been documented. They include conventional Enzyme Linked Immuno Sorbent Assays (ELISA) in microplates, one-step immuno-detection systems, fully automated systems and various non enzymatic immunological based systems like Rapid Plate Latex Agglutination (RPLA), Immuno-Magnetic Separation (IMS) or immuno-chromatography (Table 3). 

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