Ultrafiltration bovine serum albumin

Probstein et al (10) Investigated the use of detached strip type turbulence promoters in the ultrafiltration of bovine serum albumin in laminar flow. His apparatus is shown in Figure 27 the detached strip type promoters tested were circular cylinders with a diameter (D) approximately one-half (0.46) of the channel height and were across the center of the channel cross-section, transverse to the flow. 

If the channel for Fl-FFF is utilized such that cross-flow is due to a solvent of different composition that has the solvent flowing in an axial direction, continuous separation of high-molar-mass components from low-molar-mass contaminants, migrating through the accumulation membrane, can be achieved. The ratio of cross-flow rate to axial-flow rate must be suitably adjusted. The function of a continuous Fl-FFF channel as a dialysis or ultrafiltration cell was described theoretically and demonstrated in practice for the separation of bovine serum albumin from low-molar-mass methylene blue [247]. 

A continuous Fl-FFF channel analogous to a dialysis cell or ultrafiltration cell [247] was described theoretically and later demonstrated in practice for the separation of bovine serum albumin from methylene blue, various viruses, proteins, and colloidal silica particles. 

Robinson CW, Siegel MH, Condemine A, Pee C, Pahidy TZ, and Glick BR. Pulsed-electric filed crossflow ultrafiltration of bovine serum albumin. J Membr Sci 1993 80 209-220. 

One of the factors causing fouling in ultrafiltration membranes is the adsorption of solutes in the membrane pores. Since fouling, in general, has been discussed in the previous chapter, the discussion presented here will be restricted to the adsorption phenomenon. Clark et al. [37] studied the relationship between membrane fouling and protein adsorption on alumina ultrafiltration membranes. Equilibrium adsorption of bovine serum albumin (BSA) was measured by the standard static method at 7°C. Their study covered the concentration range between 1 and 10 g/1, pH values between 2 and 10 and NaCl... 

For experiments with proteins, this theory, together with data for osmotic pressure, also aids in explaining the rather unusual response of ultrafiltration rate to pressure and the virtual Independence of this response from fiber length and axial flow velocity. Osmotic pressure data are available in the literature for bovine serum albumin at pH 7.4 ( ), and osmotic pressure measurements of moderate accuracy were made by the authors on bovine calf serum. 

Bovine serum albumin (BSA) (Sigma Chemicals — Cohn fraction V) was selected as a solute material to be studied in batch cell ultrafiltration. The justification of this choice was based on the fact that BSA has been used by previous investigators their work would offer a source of comparison to our results [Blatt, et al. (1970), Kozinski and Llghtfoot (1972), Shen and Probstein (1977, 1979), Probstein (1978, 1979), Goldsmith (1971),... 

The filtered XlnD fermentation broth was initially concentrated into 20 mM Bis-Tris buffer at pH 6.8 in a 300 ml stirred ultrafiltration cell from Amicon (Beverly, MA) with a 30,000 Da molecular weight cut-off membrane. The protein was then bound to a Source Q anion exchange column (96 ml) and eluted over a 0 to 1 M NaCl gradient into 20 mM Bis-Tris at pH 6.8. The eluted XlnD peak was then reconcentrated and rerun on the Source Q column. From this run, the XlnD fractions were then pooled and buffer-exchanged into 20 mM acetate buffer at pH 5.0 with 100 mM NaCl on a Superdex 200 size exclusion column. The purity of the purified fiactions was assessed by SDS-PAGE, and the protein content was assessed by measuring the absorbance at 280 nm and by bicinchoninic acid (BCA) assay with bovine serum albumin (BSA) run as a standard. 

Mehta and Zydney [41] show a similar relationship exists for ultrafiltration membranes where transport through the membrane occurs by convective pore flow. A Robeson plot was created by taking the selectivity of an ultrafiltration membrane as the reciprocal of the protein sieving coefficient (the ratio of protein concentration in the permeate to that in the fluid adjacent to the membrane surface) and the permeability as the solvent hydraulic permeability. A plot of literature data for bovine serum albumin separation shows the existence of an upper bound. The location of the upper bound was predicted assuming the... 

PVDF-based ultrafiltration nanohybrid membranes prepared via an immersion-precipitation method using PHEMA-b/oc -PMMA-grafted silica nanoparticles as additives were shown to increase the pure water flux, improve the bovine serum albumin (BSA) rejection to a high level (>90%), and reduce membrane fouling at... 

After labelling it is necessary to terminate the reaction by the addition of an amine molecule, such as ethanolamine, and to remove any excess labelling reagent and by-products. (The presence of excess unlabelled antibody is generally not a problem.) Gel filtration, dialysis, and ultrafiltration may be used (see Section 3.2). An antimicrobial agent, e.g. sodium azide, and bovine serum albumin (BSA) are usually added to protect the labelled antibody and prevent losses BSA is also... 

Ultrafiltration membranes are used particularly for the processing of solutions of biological macromolecules. Such molecules are too small to immobilize singly on a cantilever. However, by adsorbing such molecules onto colloid probes it is possible to measure their adhesion to membrane surfaces. Such a protein-modified probe (using bovine serum albumin, BSA) and the corresponding adhesion data for two membranes is shown in Figure 6.8 [4]. 

Higuchi ef al. (1993) initated the exploration of the protein bovine serum albumin (BSA) acting as a chirally selective complexing agent for the amino acid tryptophan in an ultraflltration system. Romero and Zydney (2001) have studied in detail the stereoselective separation of a racemic mixture of D- and L-tryptophan in a solution containing BSA via ultrafiltration. The polyethersulfone UF membrane had a MWCO of 50 000 (sufficient to hold back BSA completely). L-tryptophan preferentially binds with BSA, so less L-tryptophan is present in the filtrate. The observed UF rejection, i of the tryptophan enantiomer i molecule (mol. wt. 240) as such is essentially zero. However, the feed concentration, Ctf of the tryptophan enantiomer i is related to total feed concentration, C y, by... 

Example 6.3.8 Saksena and Zydney (1994) have studied the protein transmission characteristics of a 100 000 MWCO ultrafiltration membrane (OMEGA lOOK) of polyethersul-fone using bovine serum albumin (BSA) as a model protein (mol. tvt. 66 430) in a solution of pH = 7.0 and ionic strength of 0.15 M NaCl solution. The hatch cell operation characteristics and the protein transport properties are as follows ... 

Saksena and Zydney (1994) have studied the protein transmission characteristics of a 100 000 MWCO ultrafiltration membrane (OMEGA lOOK) of polyethersulfone using a binary mixture of bovine serum albumin (BSA)... 

The aim of this section is to present an innovative methodology modeling the permeate flux decay in membrane separation processes. An ANN was developed on the basis of the experimental results collected during the ultrafiltration of bovine serum albumin (BSA) solutions under pulsating conditions (Curcio et al, 2005). 

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