Citrate buffers

Fig. 2.2.4.3 Effect of pH on the activity of recombinant ADH. The enzymatic activity was measured using the following 250 mM buffers citrate/Na2HP04, pH 4.0-7.0 TEA/HCl, pH 7.0-8.6 and glycine/NaOH, pH 8.6-11.0.

Standard labelling. 30 pi of buffer (citrate-phosphate, pH = 7.0) in Eppendorfs tube were mixed with 10 pi of Et-B 2 and 5 pi of 125I. Then 10 pi of CAT were added, the resulting mixture was vortexed for several seconds and left to react for 5 min. The reaction was quenched by 20 pi of NAT, and Nal (5 pi) was added as carrier. Standard labelling of Bu-B12 was analogous, only the buffer was replaced by the same volume of MeOH, all agents except Nal were used as methanolic solutions and the reaction was quenched by addition of 40 pi NAT. Blanks were performed in the same way, but in absence of 10 pi of the c/oio-dodecaborate salts. Experiments were performed in duplicates. 

Antigen retrieval buffer (citrate) 0.01 M citric acid-sodium citrate, pH 6.0. 

The pH was adjusted with buffers citrate (pH 3.0-4.0) 2-(N-morpholino) ethane sulphonic acid (pH 5.0-6.8) 3-(N-morpholino) propane sulphonic acid (pH 7.0-8.0) 2-(N-cyclohexylamino) ethane sulphonic acid (pH 9.0-10.0). For pH stability experiments, enzyme was incubated at different pHs for 1 h at 25°C. The residual activities were measured under standard assay condition. C. gilvus, A CHSTY, A CHBSA, CHAGE, 0 CHBSM, O A. tumefaciens, . 

Ion-exchange has been indispensable in the characterization of the transamericium elements and is also important for some of the preceding elements, particularly for tracer quantities of material. We have seen in the case of the lanthanides (Chapter 27) that the +3 ions can be eluted from a cation-exchange column by various complexing agents, such as buffered citrate, lactate or 2-hydroxybutyrate solutions, and that the elution order follows the order of the hydrated ionic radii so that the lutetium is eluted first and lanthanum last. 

Studied over pH range where there are no structural transitions in polymers (29). Dyes and polymers dissolved in 0.2M NaCl -f 0.1M buffer (citrate, phosphate, or carbonate). Viscosity of dye solutions changed by adding sucrose or glycerol to solution. Same patterns seen with polymers dissolved in water or in 3.0M NaCl + 0.1 M buffer... 

Figure 14. Dependence of transmembrane potential on proton concentration gradient in ferrocyanide-ferricyanide system (1). Potential sign is positive in part of chain with pH 7, buffer citrate-phosphate. The same dependence on membrane modified by chlorophyll in absence of redox system (2). Same dependence in presence of redox-system on nonmodified membrane.103...

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