Flow-through mode

Whereas commercial systems usually employ stirred mini vessels, laboratory-developed apparatus may be operated in flow-through mode. For mini-vessels (vials, wells), the titer plate format is typical and widely accepted. 

We have developed and tested a metabolism system and regimen which allows collection of data comparable to those from terrestrial animals. The key to our experiments is a metabolism chamber, described previously Cl3, 14) CFig. 1), which can be operated in either the static or flow-through mode. Briefly, individuals or groups of animals are held at constant temperature in the jacketed glass chamber (A), on a stainless steel screen (B), while pure water or test solution is passed over them (or held under static conditions). Solid wastes are separated in a jacketed container (C) held near 0°C to minimize microbial action, and the effluent containing dissolved metabolites is passed onto a column of nonionic macroreticular adsoprtion resin where organic solutes are adsorbed from solution (D). 

The structural elements of commercial inorganic membranes exist in three major geometries disk, tube or tube bundle, and multichannel or honeycomb monolith. The disks are primarily used in laboratories where small-scale separation or purification needs arise and the membrane filtration is often performed in the flow-through mode. The majority of industrial applications require large filtration areas (20 to over 200m ) and, therefore, the tube/tube bundle and the multichannel monolithic forms, particularly the latter, predominate. They are almost exclusively operated in the cross-flow mode. 

The quantitation of substances separated by TLC may be carried out in several ways. The most common method is to remove the spot from the plate, elute the compound from the adsorbent and measure the concentration of the compound in solution by spectrophotometry, fluorimetry, etc. The elution process has been significantly improved and facilitated with the Eluchrom instrument developed by Sandoz and marketed by Camag (see Fig.3.6). This instrument permits direct elution from the plates via small PTFE cups in a continuous flow-through mode without the necessity of removal of the adsorbent and with the minimum requirement of solvent (usually less than 1 ml). The measuring instruments used are those available for classical solution analysis. A discussion of these instruments is beyond the scope of this book. 

In order to demonstrate the performance of this electrochemical microimmunoassay platform in terms of limits of detection and dynamic range, a series of ALP tests has been conducted in 100 nL polyimide microchips. To this end, anti-phosphatase antibodies have first been immobilised on the surface of the microchannels at a concentration of 10 pg/mL in a flow-through mode (4mL of anti-ALP solution pumped at 0.4 mL/min during 10 min) so as to saturate the microchannel surface by physical adsorption. Then, the surface was blocked with a 5% BSA in phosphate buffer in order to block the free sites remaining on the surface. Solutions of ALP at various concentrations (namely 0, 0.1, 1, 10 and 100 pM) were then injected and incubated during 9 min in the... 

Water purification can be achieved by decomposition or destruction of the pollutant on contact with an electrically charged surface. In several cases permeable electrodes are used in a flow-through mode to ensure contact between the pollutant and the electrode. The type of electrode ranges from metal meshes and carbon cloths to ceramic membrane supports coated with a porous layer of electroconductive material. 

The tiypsin IMER can be applied either in off-line [38] or on-line mode [47] with ESI-MS, or with SPE-LC-MS [42, 45], or as part of a multidimensional online system (Ch. 17.5.4). The on-line digestion by means of a tiypsin IMER can be performed either in flow-through mode or in stop-flow mode [46]. Systems consisting of a trypsin IMER and an SPE-LC-MS system were reported for on-line digestion and peptide mapping of lactate dehydrogenase [42]. 

Reactor designs for AOP depend on the mode of operation (a) homogeneous or heterogeneous operation, (b) radiation source used, and (c) addition of chemical. AOP reactors are operated in either batch or flow-through mode with or without recycle. For homogeneous AOP, tank type batch reactors are often used. The flow-through mode is used in radiation-based AOP for water with low contaminant concentration (less than 10 ppm). 

Fig. 7.8 Procedure for the parallel synthesis of beaded MIPs in principle permitting flow through mode assessment of the recognition properties...

Experiments in the flow-through mode, in which the FMC operates in steady-state mode. Here, first of all, the appropriate amount of IMB in the column to be used is determined. Then, the steady state kinetic data - the dependence of the thermometric signal on substrate concentration - is measured ... 

Fig. 4.2 A scheme of a generic pure hydrogen feeding sub-system in flow-through mode. Without ejectors the same scheme refers to dead-end mode...

With the prerequisite of safe handling of organic compounds we carried out several chemical reactions in the flow-through mode. 

Figure 5 In-situ XPS data in oxygen Is region of methanol oxidation over polycrystalline copper. Total pressure 0.6 mbar, reaction temperature 673 K, flow-through mode. Gas composition as methanol oxygen molar ratio A—1 2, B—3 1,C=6 1...

Curtis S, Lee K, Blank G S, et al. (2003). Generic/matrix evaluation of SV40 clearance by anion exchange chromatography in flow-through mode. Biotechnol. Bioengin. 84(2) 179-186. 

Scheme 13 Transfer hydrogenations of alkenes and alkynes in the flow-through mode using palladium(O) particles...

Scheme 20 Multistep enzymatic preparation of UDP-galactose in the flow-through mode. GalK (galactokinase EC2.7.7.6), GalT (galactose-1-phosphate uridylyl transferase EC2.7.7.12), GalU (UDP-glucose pyrophosphorylase EC2.7.7.9), PPA (inorganic pyrophosphatase EC3.6.1.1), UMK (UMP kinase EC2.7.4.14), NDK (nucleotide diphosphate kinase EC2.7.4.6), PpK (polyphosphate kinase EC2.7.4.1)...

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