Stabilizers sodium phosphate

Figure 2 Stability of /3-poly(L-malate) measured by its activity to inhibit purified DNA polymerase a of P. polyceph-alum. The relative degree of inhibition is shown (100 rel. units refer to complete inhibition). The DNA polymerase assay was carried out in the presence of 5 /tg/ml /S-poly(L-malate) as described [4]. The polymer was preincubated for 7 days at 4°C in the following buffer solutions (50 mM) KCl/HCl (—A—). Citrate (—V—). 2-(A/-Morpholino)-ethanesulfonic acid, sodium salt (—O—). Sodium phosphate (— —). N-(2-Hydroxyethyl)piperazine-N -(2-ethanesul-fonic acid), sodium salt (— — ). N,N-b s (2-Hydroxyethyl)-glycine, sodium salt (—T—). Tris/HCl (— —). 3-(Cyclo-hexylamino)-l-propanesulfonic acid, sodium salt (— —).

Fig. 3.1.6 Effects of pH on the activity and stability of Cypridina luciferase (solid lines) and the quantum yield of Cypridina luciferin (dashed line). In the measurements of activity and quantum yield, luciferin (1 pg/ml) was luminesced in the presence of luciferase (a trace amount for the activity measurement 20 pg/ml for the quantum yield) in 20 mM buffer solutions of various pH containing 0.1M NaCl, at 20°C. In the stability measurement, luciferase (a trace amount) was left standing in 0.1 ml of the buffer solutions of various pH for 30 min at 20°C, then the activity was measured by adding 1 ml of 50 mM sodium phosphate buffer, pH 6.5, containing 0.1 M NaCl and 1 pg of luciferin, at 20°C. The activity and stability data are taken from Shimomura et al., 1961, with permission from John Wiley 8c Sons Ltd.

Small amounts of modified methylcellulose and mono-substituted sodium phosphate (both 0.1%), may be added to plugging cement [1766]. The mono-substituted sodium phosphate weakens the effect of calcium ions on modified methylcellulose and prevents its coagulation. Stabilization of the plugging solution and increased strength of the cement rock result. 

Rodriguez et al. [68] studied the stability of niclosamide in artificial gastric and intestinal juices. The gastric juice contained sodium chloride and hydrochloric acid with or without pepsin. The intestinal juice contained sodium phosphate with or without pancreatin. Niclosamide was incubated with the juices at 37°C for 6 h. The remaining intact drug and its degradation products (2-chloro-4-nitroaniline, 5-chlorosalicylic acid) were extracted with chloroform/methanol (5 1) and determined by TLC and HPLC. The drug was stable in these media for at least for 6 h. 

Remove unreacted N-acetyl homocysteine thiolactone and reaction by-products by gel filtration or dialysis against lOmM sodium phosphate, 0.15M NaCl, lOmM EDTA, pH 7.2. Other buffers suitable for individual protein stability may be used as desired. For the silver nitrate-containing reaction, removal of the silver-thiourea complex may be done by adsorption onto Dowex 50, and the protein subsequently eluted from the resin by 1M thiourea. Removal of the thiourea then may be done by gel filtration or dialysis. 

Remove the media and wash the cells twice with 8 ml of cold 0.1 M sodium phosphate, 0.15 M NaCl, pH 7.2 (PBS). Note this buffer contains a high buffer salt content to stabilize the pH during the biotinylation reaction. Do not allow the cells to remain in contact with it for more than 5 seconds to prevent detachment from the flask surface. 

Wash particles (e.g., 100 mg of 1 pm carboxylated latex beads) into coupling buffer (i.e., 50 mM MES, pH 6.0 or 50 mM sodium phosphate, pH 7.2 buffers with pH values from pH 4.5 -7.5 may be used with success however, as the pH increases the reaction rate will decrease). Suspend the particles in 5 ml coupling buffer. The addition of a dilute detergent solution may be done to increase particle stability (e.g., final concentration of 0.01 percent sodium dodecyl sulfate (SDS)). Avoid the addition of any components containing carboxylates or amines (such as acetate, glycine, Tris, imidazole, etc.). Also, avoid the presence of thiols (e.g., dithiothreitol (DTT), 2-mercaptoethanol, etc.), as these will react with EDC and effectively inactivate it. 

Most HPLC applications involving biomolecules utilize aqueous mobile phases. Critical parameters include both ionic strength and pH. Common solutes include TRIS, sodium phosphate, sodium acetate, and sodium chloride. Slightly alkaline pHs are preferable, for stability reasons. Specific examples of mobile phases include 50 mM TRIS, 25 mM KC1, and 5 mM MgCl2 (pH 7.2) for nucleotides, and 50 mM NaH2P04 (pH 7.0) and 20 mMTRIS and 0.1 M sodium acetate (pH 7.5) for both peptides and amino acids. All of these mobile phases are suitable for reverse phase or ion exchange applications. 

Fig. 20. Test of stability of weak cation exchange monolithic column (ISCO). Conditions column, 50 X4.6 mm i.d., mobile phase gradient of sodium chloride in 0.01 mol/1 sodium phosphate buffer (pH 7.6) from 0.1 to 0.5 mol/1 in 4.5 min and to 1 mol/1 in 6.5 min, overall gradient time 11 min, flow rate 10 ml/min. Peaks Ribonuclease (1), cytochrome c (2), lysozyme (3). The two separations shown in this figure were achieved 503 runs apart...

The most commonly used salts in vaccine formulations are sodium chloride, sodium phosphate, succinic acid, and sodium borate. The concentrations of the salts used in any given formulation are based on isotonicity, pH, and other stabilizers being used in the formulations. A typical range is from 5 to 20 mM salt concentration. These concentrations are also selected to reduce pain on injection and to accord rapid normalization with physiological fluid. Surfactants used in MF59 emulsion include Tween 80 and sorbitan trioleate. 

This product is made by evaporation of water from whole milk under vacuum. Low percentages of sodium phosphate, sodium citrate, calcium chloride, and/or carageenan may be added to improve its stability. The concentrate is homogenized, canned, and then sterilized under pressure at 117° C for 15 min or at 126° C for 2 min. Ultra-high temperatures (130 to 150°C for a few seconds), followed by aseptic packaging, have been used with some success but have found limited commercial application. 

Electrophoretic Methods. Several electrophoretic procedures have been developed to fractionate or purify the various caseins (McKenzie 1971C Thompson 1971 Whitney 1977). Wake and Baldwin (1961) fractionated whole casein by zone electrophoresis on cellulose powder in 7 M urea and 0.02 ionic strength sodium phosphate buffer at pH 7 and 5°C. Payens and co-workers employed several somewhat different electrophoretic conditions for the fractionation and purification of the caseins on cellulose columns (Payens 1961 Schmidt and Payens 1963 Schmidt 1967). Three fractions, as-, k-, and /3-caseins, were separated at pH 7.5 and 30°C with 4.6 M urea-barbiturate buffer. The purification of asi-casein and the separation of the genetic variants of K-casein were accomplished by altering the electrophoretic conditions. Manson (1965) fractionated acid casein on a starch gel column stabilized by a density gradient at 25 °C. 

Prepare the protein or macromolecule to be thiolated in a non-amine-containing buffer at pH 8.0. For the modification of ribosomal proteins (often cited in the literature) use 50 mM triethanolamine hydrochloride, 1 mM MgCl2, 50 mM KC1, pH 8. The magnesium and potassium salts are for stabilization of some ribosomal proteins. If other proteins are to be thiolated, the same buffer may be used without added salts for stabilization. Alternatively, 50 mM sodium phosphate, 0.15 M NaCl, pH 8, or 0.1 M sodium borate, pH 8.0 may be used. For the modification of polysaccharides, use 20 mM sodium borax, pH 10, to produce reactivity toward carbohydrate hydroxyl residues. Dissolve the protein to be modified at a concentration of 10 mg/ml in the reaction buffer of choice. Lower concentrations also may be used with a proportional scaling back of added 2-iminothiolane. 

The "mild" NaBH4 reduction was done at 22°C (room temperature) and pH 8.0 The slightly alkaline conditions were necessary to maintain reasonable stability for the NaBH4 reagent. Sodium borohydride, 0.1 mL of 0.25 M NaBH4 in 0.1 M NaOH, was added to test solutions containing 1 mg of cellulose suspended in 0.785 mL of 0.1 M sodium phosphate, pH 8.0 Reaction mixtures were mixed and allowed to react for up to 90 min at room temperature. Reactions were terminated at selected times by the addition of 20 iL of 37% (w/v) HC1. Terminated reaction mixtures were typically allowed to stand for 30 min prior to neutralization by the addition of 95 pL of 2 N NaOH. Separate experiments showed that residual sodium borohydride could not be detected following the low-pH 30-min incubation period. 

The immobilization of trimeric LHCII is demonstrated in Fig. 13(B). After the nickel ion activation (5), a 1 pM solution of trimeric recombinant LHCII prepared in NaP + DM buffer (20 mM sodium phosphate, pH 7.4, 0.1 % (w/v) n-dodecyl-/ -D-maltoside) was introduced into the flow cell (1). For each cycle, the protein solution was incubated in the loop for 30 min, followed by buffer rinse (2), EDTA (3), and SDS (4) regeneration. EDTA was used to competitively chelate the nickel ions and break the linkage between NTA and Histidine. SDS, as mentioned in Section 4.2, was used to detach any remaining physically adsorbed proteins. As shown in Fig. 13(B), the immobilization/regeneration cycles from (1) to (5) can be well reproduced and the baseline after every cycle stabilized at a response close to the starting level. This indicates that the... 

Haifeng L, Yuwen L, Xiaomin C et al (2008) Effects of sodium phosphate buffer on horseradish peroxidase thermal stability. J Thermal Anal Calorim 93 569-574... 

Poly(vinyl alcohol). Deposition is achieved by flushing the capillary with a 10% aqueous solution of 50 kDa PVA (99% or more hydrolyzed), pushing the coating solution out of the column with a stream of nitrogen, and then heating the capillary at 140°C under a stream of nitrogen. This produces capillaries with an efficiency of greater than a million plates, essentially no EOF, stability up to pH 10, and the ability to separate basic or acidic proteins (see Fig. 321). A 50 m M sodium phosphate buffer at pH 3.0 is used, and CE is carried out at 30 kV at 20°C. 

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