Capillary electrophoresis reaction condition

Figure 11 illustrates the CE separation of synthetic polythymidylic oligomers. The capillary gel electrophoresis separation of this sample has previously been described by Paulus and Ohms (21) using UV-absorbance detection. The polythymidylic 50-mer sample was synthesized with the reaction conditions purposely adjusted to increase the failure rate at every fifth base, beginning with the 15-mer. 

Similar results were obtained using cyt P450 as the enzyme. DNA/(Cyt P450cam/ST-ds-DNA)2 films were incubated with styrene and hydrogen peroxide, and a rapid increase in SWV peak current in the first 5 min was followed by a slower increase from 5 to 30 min (Fig. 10a). Capillary electrophoresis and HPLC-MS analyses of DNA in thin films that were reacted with styrene oxide, and then hydrolyzed, confirmed formation of known styrene oxide adducts of DNA bases under similar reaction conditions. 

The experiments were run in a continuous-flow stirred tank reactor (CSTR) (fig. 6.2) with the reaction system at a nonequilibrium stationary state, such that the reactions run spontaneously from glucose to G3P and 3PG. The concentrations of the species at this state are close to those of physiological conditions. The metabolites G6P, F6P, F1,6BP, DHAP, G3P, and 3PG were detected and analyzed by capillary electrophoresis. Typical relative errors were 4% for G6P, 11% for F6P, 15% for F1,6BP, 9% for DHAP, 6% for 3PG and 3% for G3P. 

Cao, C.X., Zhang, W., Qin, W.H., Li, S., Zhu, W., and Liu, W., Quantitative predictions to conditions of zwitterionic stacking by transient moving chemical reaction boundary created with weak electrolyte buffers in capillary electrophoresis. Anal. Chem., 77, 955, 2005. 

The target product can be obtained by the reaction between L, 4-butane sultone and /3-CD in alkaline solution. Different reaction conditions can have different average DS. Capillary electrophoresis is always applied to analyze the differences in the composition of product mixtiue [9]. 

Capillary zone electrophoresis (CZE), the most widely used CE mode, is also the mode most frequently used for performing CE immunodetection. The first assay of immunoaffinity capillary electrophoresis described was carried out with CZE in noncompetitive format (Fig. 8a) [79,80]. This format has been used to determine a protein in a matrix as complex as human serum by incubating the sample with specific antibody for 1 hr before the introduction onto the CE column [81]. The size of the immunocomplex peak was seen to increase with incubation time. One drawback of this method is the long incubation time needed because of the slow reaction kinetics of formation of Ab-Ag complex. To prevent noticeable complex dissociation during the analysis, conditions to achieve a separation time shorter than 3 min were chosen. 

Abstract Medical studies established that vancomycin and other related macro-cyclic antibiotics have an enhanced antimicrobial activity when they are associated as dimers. The carbohydrate units attached to the vancomycin basket have an essential role in the dimerization reaction. Covalently synthesized dimers were found active against vancomycin-resistant bacterial strains. A great similarity between antibiotic potential and enantioselectivity was established. A covalent vancomycin dimer was studied in capillary electrophoresis producing excellent chiral separation of dansyl amino acids. Balhimycin is a macrocyclic glycopeptide stmcturally similar to vancomycin. The small differences are, however, responsible for drastic differences in enantioselectivity in the same experimental conditions. Contributions from studies examining vancomycin s mechanism for antimicrobial activity have substantially aided our understanding of its mechanism in chiral recognition. 

Fig. 3.161. (A) Zone electrophoresis patterns of FITC-labelled transferrin samples by fluorescence detection. The unbound dye (providing a main peak and several minor ones) was not removed from the samples. Experimental conditions background electrolyte, 100 mM borate buffer, pH 8.3 voltage, 20 kV capillary 59 cm (effective length 41 cm) X 75 pm i.d. injection of samples 100 mbar x s 20°C detection with fluorescence detector (240 - 400 nm, broadband excitation filter and a 495 nm cut-off emmision filter). The reaction was left to continue for 20 h, and the reaction mixtures contained 13 pm (1 mg/ml) Tf and (a) 0.01 mM FITC, (b) 0.1 mM FITC, and 1 mM FITC. (B) Zone electrophoresis patterns of an FITC-labelled transferrin sample by simultaneous fluorescence (upper trace, left axis) and UV detection (lower trace, right axis). The unbound dye shows several peaks with both detections. Experimental conditions background electrolyte, 100 mM borate buffer, pH 8.3 voltage, 20 kV capillary 59 cm (effective length fluorescence 41 cm, UV 50.5 cm) X 75 pm i.d. injection of samples 100 mbar X s 20°C detection with fluorescence detector (240 - 400 nm, broadband excitation filter and a 495 nm cut off emmision filter). The reaction was left to continue for 20 h, and the reaction mixtures contained 6.5 pm (0.5 mg/ml) Tf and 0.1 mM FITC. Reprinted with permission from T. Konecsni et al. [199].

Acid hydrolysis under standard conditions (6M HC1, 110 °C, 24 h) leads to partial decomposition of selenocystine and selenocysteine derivatives, thus making quantification of this amino acid by amino acid analysis difficult. Similarly, acid hydrolysis of 5e-[2-(4-pyr-idinyl)ethyl]selenocysteine peptides, obtained by reduction of the selenocystine peptides with NaBH4 and reaction with 4-vinylpyridine, results in partial decomposition. This de-rivatization, however, is useful for the enantiomeric resolution of the acid hydrolysates by capillary zone electrophoresis by applying host-guest complexation with crown ethers.11" 22 ... 

---