Dialyzers lengths

Remove the dialyzed protein solution and estimate the amount of protein recovered (see Note 14). Dilute 100 pL of the dialyzed protein solution with 900 pL of BBS. Using BBS as a blank, read the absorbance of the diluted solution at 280 nm. A 1-mg/mL solution of protein consisting mainly of immunoglobulins will have an absorbance of approx 1.4 if read in a cuvet with a 1-cm path length. Therefore,... 

The length of the reaction, which may reach 10-12 days, could limit the reproducibility and applicability of this reaction. Additionally, the method used to recover the product at the end of the reaction can lead to side-reactions. In some procedures (e.g., Halpin and Richardson, 1985 Bertrand-Harb etui, 1991), the reaction medium at the end of the reaction time was combined with an equal volume of water, then dialyzed against water for several days, which can lead to deesterification (Bertrand-Harb et al., 1991). Another way to recover the reaction product was by drying under vacuum (Briand etal., 1995). 

Circular dichroism (CD) spectra were collected on an AVIV model 62DS spectropolarimeter using a 0.2 mm path length cell. Protein samples were dialyzed against buffer containing 20 mM sodium phosphate (pH 7.0), 50 mM NaCl, ImM BME. Eive separate spectra with a step size of 0.5 nm and a 1.5 nm bandwidth were averaged to obtain the final spectrum for each protein sample. The temperature during the scans was maintained at 25°C with a water-... 

Isotachopherogreuns of the seven polymer solutions are shown in Figures 6-8. Copolymer 78/22 and both the upper and lower phases of copolymers 60/40 and 40/60 contain two distinct zones. One component in each copolymer had an effective mobility Identical with that of AMPS homopolymer and Its zone length increased proportionately when authentic AMPS-100 was added. AMPS monomer has a lower effective mobility than the homopolymer. No monomer was detected In these dialyzed copolymer samples. 

In the previous section, mess tmasfer was discussed for a single point on (he membrane For practical applications, this analysis must be extended to describe irises transfer for the dialyzer as a whole. Neglecliug convective contributions, we can write the following equation for the mass of solute dm transferred across an element of membrane of length dx tied area dA per unit time (Fig. 21.1 -S) ... 

In order to balance the pressures on the two sides of the channels, the channel with the lower pressure (usually the donor stream) can be connected to a flow restrictor located downstream of the dialyzer. The restrictor is simply a length of thin tubing. Such measures may become necessary when one channel, usually the acceptor stream, is connected with packed reactors which significantly increase the flow impedance. On the other hand, in order to minimize clogging of the membranes, an increase in pressure on the acceptor side may be necessary when samples containing suspended sediments (e.g. urine) are analyzed, possibly with some sacrifice in the dialysis efficiency. 

Colton et al. used a Graetz-type solution to calculate a log-mean feed-side Sherwood mindin (SHf = kfh/S), where A is the chaiind height) for huninar flow in a flat duct with permeable walls as a function of the wail Sherwood number (Shw, = and the dimensionless length of the dialyzer. This analysis... 

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