Tri-sodium citrate

X Sodium chloride-sodium citrate (SSC) Dissolve 17.5g NaCl and 8.8g Tri sodium citrate in 80 mL dH20. pH to 7.0 and make up to 100 mL with dH20. This should be autoclaved and then stored at room temperature. 

Prepare citrate buffer pH 3.5 as follows Dissolve 2.56 g citric acid and 2.36 g tri-sodium citrate in 50 mL double-distilled water. Stir with magnetic stirrer for 15 min. The buffer may be stored at 4°C for approximately 2 months. 

Slot and Geuze developed a method that combines tannic acid with tri-sodium citrate as reducing agents. They described the optimal conditions to obtain mono-disperse sols of 3 to 15 nm, varying the amount of tannic acid to be added. 

From citrate buffers two the most popular are solutions containing in different proportions 0.1 M citric acid and 0.1 M tri-sodium citrate (pH 3.0-6.2) and the Mcllvaine citrate-phosphate buffer [40], having in different proportion 0.1 M citric acid and 0.2 M disodium hydrogen phosphate (pH 2.6-7 6). This buffer is actually a mixture of two buffers, it can be prepared fi om HjCit, HjPO and NaOH or NajCit and H3PO4 or from some other combinations. The citrate-phosphate buffer of constant ionic strength 0.5 and 1.0 M is prepared by adding KCl [41]. 

Potassium dihydrogen citrate 0.05 molal solution (pH=3.776 at 25 °C) is used for calibration purposes because it exhibits better stability than primary pH reference buffer solutions of tartrate or phthalate [44, 45]. The saline sodium citrate buffer (SSC) prepared from tri-sodium citrate and sodium chloride (pH=7.0) is applied in biochemistry. Citric buffers with different HjCit Na3Cit ratios are clinically effective, for example in reducing gastric acidity [46-48]. Compositions of buffers and corresponding pH values are presented in Table 3.7. 

In order to illustrate distribution of species in buffers and buffer capacities p, the slightly modified Okamoto et al. [69] computer program was used in the case of two citric acid + tri-sodium citrate buffers with total concentration of c=0.1 M and c=0.2 M. The speciation of both buffers as a function of pH is plotted in Fig. 3.19. 

Sadeghi R, Golabiazar R, Shekaari H (2010) The salting effect and phase separation in aqueous solutions of tri-sodium citrate and l-butyl-3-methylimidazolium bromide. J Chem Thermodyn 42 441-453... 

Tyrosinase (PPO) [E.C 1.14.18.1] was purchased from Sigma. Pyrrole was purchased from Aldrich and sodium dodecyl sulfate (SDS) from Sigma. Pyrrole was distilled before use. MBTH, acetone and sulfuric acid used in spectrophotometric activity determination of PPO were also obtained from Sigma. For preparation of citrate buffer, tri-sodium citrate-2 hydrate and citric acid were used as received. 

For most free amino acids and small peptides, a mixture of alcohol with water is a typical mobile phase composition in the reversed-phase mode for glycopeptide CSPs. For some bifunctional amino acids and most other compounds, however, aqueous buffer is usually necessary to enhance resolution. The types of buffers dictate the retention, efficiency and - to a lesser effect - selectivity of analytes. Tri-ethylammonium acetate and ammonium nitrate are the most effective buffer systems, while sodium citrate is also effective for the separation of profens on vancomycin CSP, and ammonium acetate is the most appropriate for LC/MS applications. 

Assay of scintillon activity. A small volume (5-50 xl) of a scintillon sample is mixed with 1ml of 50 mM Tris-HCl, pH 8.0, containing 10 mM EDTA and 1 mM DTT. To this mixture, 1 ml of 0.2 M sodium citrate, pH 5.2 (or 30 mM acetic acid) is injected and the light emission is measured. 

After 2 h incubation of the prepared antibody beads with UV-crosslinked extract in a cold room, the beads are washed 4 x with 100 /A RIPA buffer (50 mMTris-HCl pH 7.5, 150 rnMNaCl, 1% NP-40, 0.5% sodium deoxycholate, and 0.1% SDS) and lx with genomic DNA lysis buffer (50 mM Tris, pH 7.4, 10 mM EDTA, 500 mM NaCl, 2.5 mM DTT, 0.5 mM spermidine, 1% Triton X-100). Approximately 300 /(I of PK solution (1 mg/ml proteinase K in genomic DNA lysis buffer and 0.2 U//A RNase inhibitor) is added to the total lysate previously kept on ice and the beads are then incubated at 37° for 30 min. Gently flick the tubes to resuspend the beads every 10 min during the incubation. After removal of the proteinase K solution, 300 /A of RNA extraction solution (4 M guanidine thiocyanate, 0.5% sarkosyl, and 25 mM sodium citrate, pH7) is added to the beads, incubated for 10 min and the supernatant is mixed with 30 fig yeast tRNA (as a carrier) and 30 fil of 3 M sodium acetate. The RNA solution is phenol-chloroform extracted, ethanol-precipitated, and the pellet washed once with 70% ethanol. The dry pellet is used for 1st strand cDNA synthesis, followed by PCR analysis. The removal of proteins... 

Generally Tris-HCl buffer produces better results at higher pH levels (e.g., pH 10.0) than do some other buffers. On the other hand, sodium citrate buffer increases the intensity and extent of immunostaining of a wide variety of tissue antigens at pH 6.0. EDTA-NaOH (1 mM) at pH 8.0 also yields satisfying results. Although relatively high pH solutions, such... 

The following three levels of heating durations and three pH levels of the epitope retrieval fluid (sodium citrate buffer and Tris-HCl buffer) have been recommended to determine the optimal protocol for the retrieval of an epitope (Shi et al., 1996a). 

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