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Membrane cutoff

Remove excess reactants and block remaining sulfo-NHS ester sites by dialysis against 50mM Tris, pH 7.4. Use a membrane cutoff appropriate to allow passage of the protein being coupled, but retention of the protein-QD conjugate. [Pg.495]

The impact of parameters such as the ratio of protein mass to the membrane cutoff (A), or the effect of the membrane material during permeation, on their structure/ function, is currently unknown and constitutes an essential requisite for the full development and implementation of membrane processes for the selective fractionation of proteins. [Pg.258]

Channel height (plate-type filter). Membrane cutoff at 90% rejection. Cutoff not available. [Pg.424]

The overall performance of membranes is related to two main characteristics their permeability and their permselectivity (separation ability). For porous membranes, the selectivity and the membrane cutoff depend on the pore size and the pore size distribution of the separative layer. The membrane permeability and the membrane thickness fix the viscous flux for a given transmembrane pressure. The viscous flux of a liquid, J, across a porous medium is given by Darcy s law ... [Pg.446]

High molecular weight, selected for each UF membrane cutoff... [Pg.857]

Many studies have pointed out that a CR ultrafilter can operate at a flux level of 300-400 L/(m h) when white waters are filtered. The reduction in organic compounds (COD, UV absorption at 280 nm, or sugar) using a UF membrane (cutoff 30-200 kg/mol) has been from 10% to 40% depending on the process water. The reduction of anionic trash is usually better (30%-90%) [48]. A pilot study showed that a high-shear filter (CR-nanofiltration unit) could operate without any pretreatment at a flux level of 50-120 L/(m h) when paper null clear filtrate was filtered. Mechanical erosion was a problem with some of the NF membranes used [18]. [Pg.995]

This approach has subsequently been used in symmetrical FIFFF [7,8], where the sample is injected in either the forward or backward focusing flow streams (Fig. 1). Lyven et al. [7] showed a virtually quantitative recovery for preconcentration of 1.7 to over 100 mL of low-molecular-weight polymers and natural water colloids (Fig. 2) with a molecular weight of the same order as the membrane cutoff by optimizing injection flows, membrane, and carrier. Injection in both the forward and backward focusing flow stream was evaluated. An experimental approach was used to determine the minimum time for sample loading and focusing. In or-... [Pg.892]

When the substrate has a molecular weight lower than the membrane cutoff, enzymes can be covalently bound either to the "active side" of the membrane or within the sponge-like substructure of the membrane. [Pg.457]

The mass balance problem can be solved readily for organic carbon. The filtrates of each fraction filtered sequentially are missing organic matter of a size larger than the membrane cutoff. By measuring either the retentate or filtrate TOC in mg/L, the mass of TOC in each successive filtrate fraction can be determined if it is assumed that (I) the TOC of molecular size less than the membrane cutoff passes in proportion to the volume (2) the membrane behaves ideally as a molecular sieve at each cutoff and (3) the volume is known. Given these conditions, a system of equations (Table V) for either retentate or filtrate fractions can be... [Pg.149]

The emulsifier was a blend of two nonlonlc-polymerlc surfactants, polyCvlnyl alchohol), PVA, and poly(ethylene oxide), FEO. Both polymers have molecular weights In excess of the membrane cutoff of 50,000 daltons. The average molecular weights of PVA and PEO are 125,000 and 100,000 respectively. [Pg.168]

The crude extract (85 mg of protein in 40 ml) is heated at 70° for 10 min and centrifuged at 5000g at 4° for 10 min the supernatant is concentrated by ultrafiltration in an Amicon (Danvers, MA) cell (membrane cutoff 2000 Da), subjected to a second heating at 75° for 10 min, and centrifuged as above. Following the thermoprecipitation steps, about 80% of the E. coli proteins are removed. [Pg.71]

MUPs were purified according to Cavaggioni et al., 1990. Briefly, urine from adult male Swiss mice (3 to 5 months old) was collected in metabolic cages and frozen. It was then concentrated on membranes (cutoff 10000 Da) and chromatographed through a mo-... [Pg.361]

Sample preparation Place 0.5 cm of a dried blood stain with 25 p.L water in an Ultrafree-MC centrifugal filter with a PTTK polysulfone membrane (cutoff 30 000 Da), let stand for 45 min, centrifuge for 10 min, inject an aliquot of the filtrate. [Pg.206]


See other pages where Membrane cutoff is mentioned: [Pg.497]    [Pg.260]    [Pg.1239]    [Pg.2541]    [Pg.985]    [Pg.986]    [Pg.1386]    [Pg.394]    [Pg.22]    [Pg.732]   
See also in sourсe #XX -- [ Pg.258 ]




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Cutoff

Nominal molecular weight cutoff ultrafiltration membranes

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