Amicon

The sampling of solution for activity measurement is carried out by filtration with 0.22 pm Millex filter (Millipore Co.) which is encapsuled and attached to a syringe for handy operation. The randomly selected filtrates are further passed through Amicon Centriflo membrane filter (CF-25) of 2 nm pore size. The activities measured for the filtrates from the two different pore sizes are observed to be identical within experimental error. Activities are measured by a liquid scintillation counter. For each sample solution, triplicate samplings and activity measurements are undertaken and the average of three values is used for calculation. Absorption spectra of experimental solutions are measured using a Beckman UV 5260 spectrophotometer for the analysis of oxidation states of dissolved Pu ions. 

Water Permeation and Solute Separation through the Membrane. The measurements of water permeability of the 67 membranes prepared under different conditions were carried out by using an Amicon Diaflo Cell (effective membrane area, 13.9 cm2) under a pressure of 3 kg/cm2 at 25 °C. Some results are listed in Table 1067. It is apparent that much higher water absorption and permeability than the cellulosic membrane are characteristic of the 67 membranes prepared by both the casting polymerization and conventional casting. 

Total polysaccharides were recovered in the ultrafiltration retentates on a Carbosep M5 membrane (Tech-Sep, MWCO 20 kDa) in the case of the red wine, or on a Centricon 30 membrane (Amicon, MWCO 30 kDa) in the ease of the apple and tomato juices. RG-II purification from the total polysaccharide coneentrates included, if necessary, several chromatography steps ... 

Fractionation of the Sediment Extract. Ultrafiltration methods (17) have produced some useful data about the nominal molecular size of the active component. Crude sediment extract was filtered (Amicon, 50 psi) and separated into three fractions having the following nominal molecular fractions <10,000, <2,000, <500. The fractions were tested for hydrilla-inhibition, and the two lower M.W. fractions proved to be inactive against the plant. The fraction having a M.W. greater than 2,000 but less than 10,000 showed inhibitory action somewhat enhanced over that of the crude extract (12). 

Material. Methotrexate-y-hydrazide was prepared by a modified procedure described by Rosowsky (14). Divinyl ether-maleic anhydride copolymer was purchased from Hercules Incorporated (Wilmington, DE) and had an average molecular weight of 11,400. Centriprep-10 concentrators were purchased from Amicon (Danvers, MA). 

For proper bookkeeping and archiving each sample tube must be uniquely labeled. A label such as brownish fraction number 73 from DEAE column, possibly containing a new iron-sulfur protein, concentrated over Amicon 30, reduced... 

Pool fractions containing PPO and concentrate to 5 mL using YM 10 Amicon ultrafiltration filters. 

Ultrafiltration was carried out in an Amicon stirred cell, 65 ml capacity, at 4 C with continuous stirring under C02 pressure until 25 ml filtrate had been collected. MWC0 = nominal molecular weight cut-off of the membrane. 

Figure 1. Production of Fe(II) on irradiation of pH 4.0 solutions of distilled, deionized water and 0.1M NaCl and a pH 6.5 solution of 0.1M NaCl/2mM NaHC03 containing 3.5pM am-FeOOH. The ultrafilterability of the iron through a membrane exhibiting a nominal molecular weight cutoff of 10,000 (Amicon PM10) in the pH 4.0 study is also shown. Light source simulated solar spectrum of total intensity 300 pEinsteins cm-2 min-1. (Reproduced from Ref. 32. Copyright 1984, American Chemical Society.)...

Cytochrome P-450 fractions were pooled and the free Emulgen 913 removed from the enzyme preparation by stirring with Amberlite XAD-2 beads followed by filtration. The filtrate was concentrated in an Amicon ultrafiltration cell using a YM 10 Diaflo membrane. Dialysis was carried out in 2 liters of Buffer I for 24 hr when required. The fractions containing cytochrome P-450 were stored under nitrogen in 0.5 ml aliquots at -62°. 

The material eluted was loaded onto the column once more subsequently, the column was washed with 350 mL of 20 mM KH2PO4 (pH 7.4) and then with 350 mL of 20 him potassium phosphate buffer (pH 7.4) supplemented with 1 mM imidazole. PAMO-P3 was eluted with 100 mL of 50 mM tris-HCl (pH 7.4) containing 200 mM imidazole. In total, 25 mL of yellow eluate was collected and concentrated to 12.5 mL by centrifuge filters (Amicon, MWCO 10000). 

In general, a threefold dilution of the injected sample volume is to be expected. If necessary, the antibodies can be concentrated after this step. This can be conveniently accomplished using Centricon centrifuge concentrators (Amicon). 

An F/P ratio of two to five is optimal, since ratios below this yield low signals, whereas higher ratios show high background. If the F/P ratios are too low, repeat the coupling reaction using fresh fluorochrome solution. The IgG solution needs to be concentrated prior to reconjugation (e.g., Centricon-30 microconcentrator from Amicon Co., Beverly, MA, can be used to concentrate the IgG solntion). 

Amicone L, Spagnoli FM, Spath G, Giordano S, Tommasini C, Bernardini S et al (1997). Transgenic expression in the liver of truncated Met blocks apoptosis and permits immortalization of hepatocytes. EMBOJIQ 495-503. 

Prq[iaration of clarified digests sludge. Samples were removed under anaerobic conditions and moved immediately into the anaerobic chamber. Before analysis, the samples were clarified by centrifugation and filtration with 0.22-jLtm Acrodisc filters. Concentrated digester supernatant was also examined, and it was prepared by ultrafiltration in the anaerobic chamber with an Amicon stirred cell ultraconcentrator and Amicon PMIO membranes. 

D-glucosidase preparations were concentrated and dialyzed with an Amicon model DC-2 Hollow Fiber Ultraconcentrator equipped with HlPlO-20 or HlPlOO-20 cartridges. 

Diafiltered -D-g uoosidase. This enzyme grade was prepared by the exhaustive ultradialysis of Novozym SP188 with 10 mM phosphate buffer pH 6.5. Amicon HIPIO-20 hollow fiber cartridges were used for this purpose. 

Step II Diafiltration. Extracts to be fractionated by HPLC were diafiltered into buffer A using Centricon 10 microconcentrators (Amicon Div., Grace Co., Danvers, MA) and then passed through 0.22 jim filters. 

The 600 mL eluate was concentrated at 4°C, the temperature used for all further purification steps, with an Amicon YM-2 membrane to 30 mL and divided into three equal parts. Each was loaded on to a 20-mm i.d., 900-mm-long Fractogel TSK DEAE-650S column and eluted with 4 mL/min of 0.05A/ sodium phosphate buffer at pH 7.2. 

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