Application of capillary electrophoresis to the analysis of metal-containing pharmaceuticals

The efficiency of the development and application of pharmaceuticals, including those based on metal compounds, essentially depends on the sophistication of the analytical procedure in use. The review is devoted to the state-of-the-art capillary electrophoresis (CE) as an analytical technique for studying drug preparations based on metal complexes. Examples are given to characterize the advantages of CE in the determination of the active principle and its metabolites, the evaluation of pharmacological properties, and the screening of compounds, as well as progress in the development of its methodology. In conclusion, the disadvantages of CE in this area and ways around these problems are critically considered in order to further develop this technique and to introduce it into clinical practice.     

Application of capillary electrophoresis to the analysis of soluble chromatin

Capillary electrophoresis (CE) has been applied to study DNA-protein complexes using as the test system soluble chromatin from chicken erythrocytes and rapidly proliferated cultured Chinese hamster fibroblast-like cells B11-dii-FAF-28. Separation was performed with home-made CE apparatus, using a regulated high-voltage power supply, UV-detector and fused silica capillaries with inner diameter 75 microm. The heterogeneity of nucleosomal particles with different DNA lengths after micrococcal nuclease digestion was detected.     

Pesticide analysis by capillary electrophoresis

In this work, a critical and updated revision of the current situation of the analysis of pesticides by Capillary Electrophoresis (CE) is presented. The review has been written in two main sections. The first one presents a thorough revision of the various offline and on-line sample preconcentration procedures that have been used in conjunction with CE to analyze these compounds. The second part reviews the various detection strategies (i.e., UV, LIF, MS, and electrochemical) and CE modes that have been applied to the analysis of pesticides. Future trends that can be expected from this hot research area are also discussed.     

Single-strand conformation polymorphism analysis to detect the p53 mutation in colon tumor samples by capillary electrophoresis

The polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) technique is developed for the detection of point mutations in DNA samples, and is very useful in the research of tumors. The traditional SSCP was carried out with slab gel electrophoresis (SGE), but this is time-consuming and labor-intensive, particularly for clinical diagnoses. We have developed a capillary electrophoresis (CE) method for SSCP detection with a linear polyacrylamide gel solution as the sieving matrix. Twenty colon tumor samples were detected with SSCP-CE and the point mutation in exon 7 of the p53 gene was found in six of the samples. Based on the sequencing results, the accuracy of SSCP-CE was better than that of SSCP-SGE. We hope this rapid and convenient method could be applied in the clinical diagnosis of tumors soon.     

Application of capillary electrophoresis to the analysis of inorganic ions in environmental samples

A comprehensive review is presented of the state-of-the-art of capillary electrophoresis for application to the analysis of inorganic species, mainly ions, in environmental samples. This brief review covers the developments principally in sensitivity and matrix interference for the determination of inorganic ions in the following samples: drinking, mineral, surface, and ground waters, rainwater, snow, seawater, brine and waste waters, aerosol, and others. References published mainly from 1995 to 1997 were summarized in this review.     

Application of nonaqueous capillary electrophoresis to the simultaneous analysis of anionic surfactants

In aqueous capillary electrophoresis selectivity between different alkyl chain lengths within one anionic surfactant-group markedly exceeds selectivity between different functionalities at a given chain length. Peak identification and quantitative analysis in complex mixtures is almost impossible, especially, if the sample contains ethoxylated surfactants as well. Applying nonaqueous capillary electrophoresis (NACE), significant differences in the mobilities of the various functionalities can be generated to exceed at satisfying separation. In this paper, method development of NACE systems is described and the application of these systems to anionic surfactant analysis in real sample matrices is documented.     

Energy drink analysis by capillary electrophoresis

Caffeine and vitamins C, PP, and B6 have been determined in energy drinks by capillary electrophoresis. Its advantages and disadvantages over high-performance liquid chromatography have been considered and the influence of analysis conditions on the error of analysis and error sources in capillary electrophoresis have been estimated.     

Element speciation analysis by capillary electrophoresis

An overview of recent developments in the application of capillary electrophoresis to simultaneous separation and determination of different chemical forms of an inorganic element is presented, with particular emphasis placed on metal speciation analysis. Examples of species analysis are addressed, covering metal ions in different oxidation states, metal complexes with inorganic and organic ligands, metalloid oxoanions, organometallic compounds, ionic non-metal species, etc. The speciation performance of capillary electrophoresis is illustrated by a number of practically relevant applications. The method's strengths and current limitations with regard to chemical speciation studies are critically discussed.     

Application of capillary electrophoresis in peptide research.

Comparison of high performance liquid chromatograms (HPLC) with capillary electrophoresis shows the latter to be superior in many cases owing to rapid separation, high resolution and high sensitivity. This is demonstrated with two examples (i) the isolation of natural peptides from bovine tissue and (ii) characterization of a synthetic peptide mixture with the natural sequence (fragment) of the human immunodeficiency virus (HIV) transmembrane glycoprotein gp 41 env.     

Analysis of isomeric glutamyl peptides by capillary electrophoresis. Application to stability studies

Capillary electrophoresis has been used for the separation of the glutamyl tripeptides Gly-alpha-Glu-Phe-NH2 and Phe-alpha-Glu-Gly-NH2 including their potential degradation and isomerization products Gly-gamma-Glu-Phe-NH2, alpha-Glu-Phe-NH2, gamma-Glu-Phe-NH2 and Phe-NH2 as well as Phe-gamma-Glu-Gly-NH2, Phe-Glu and Phe, respectively. Between pH 2.2 and pH 10.0 the effective mobilities of the glutamyl peptides have been investigated. Using histidine hydrochloride as internal standard at pH 2.2 linear calibration curves for both assays were obtained for a concentration range from 10 microg ml(-1) to 3.5 mg ml(-1). The assay was applied to analyze the degradation of the tripeptides in solution at pH 7 and pH 3 at 70 degrees C. Hydrolysis and isomerization of the glutamyl peptides were found in the incubation mixtures.     

High-throughput analysis of telomerase by capillary electrophoresis

The enzyme telomerase is expressed in (85-90)% of all human cancers, but not in normal, non-stem cell somatic tissues. Clinical assays for telomerase in easily obtained body fluids would have great utility as noninvasive, cost-effective methods for the early detection of cancer. The most commonly used method for the detection and quantification of telomerase enzyme activity is the polymerase chain reaction (PCR)-based assay known as the telomerase repeat amplification protocol or TRAP assay. Most of the TRAP assay systems use a slab-gel based electrophoresis system to size and quantify the PCR-amplified extension products. We are developing high-throughput capillary electrophoresis (CE) methods for the analysis of TRAP/PCR products. The TRAP assay was conducted on lysates of the human lung cancer cell line A-549 in reactions containing 5-100 cells. TRAP/PCR products were generated using a fluorescent 4,7,2'4'5'7',-hexachloro-6-carboxyfluorescein(HEX)-labeled TS primer and analyzed on the Applied Biosystems Model 310 CE system using POP4 polymer. After analysis with GeneScan and Genotyper software, the total peak areas of the TRAP ladder extension products were computed using Microsoft Excel. Results were compared with unlabeled TRAP/PCR products analyzed on the Bio-Rad BioFocus 3000 CE system using 6% high molecular weight polyvinylpyrrolidone (HMW PVP) polymer and SYBR Green I dye. Both CE systems were able to resolve the TRAP ladder products with high reproducibility and sensitivity (5-15 cells). With the appropriate robotic sample handling system, these CE methods would enable performing the telomerase TRAP assay with increased sensitivity, reproducibility and automation over slab-gel methods.     

Application of capillary electrophoresis to the simultaneous determination of betaines in plants.

The simultaneous determination of betaines, the key compounds for osmotic regulation in plants, was established by capillary electrophoresis (CE). After four betaines, glycine betaine (GB), beta-alanine betaine (AB), proline betaine (PB), and 2-hydroxyproline betaine (HPB), were esterified with p-bromophenacyl bromide, the esters were electrophoresed in 100 mM sodium phosphate at pH 3.0. A low-pH condition in CE and esterification gave an advantage of resolving each of the ester peaks as well as those of the unreacted reagent and other components. Furthermore, the addition of 4% polyethylene glycol (PEG) gave a better resolution of 4 peaks, resulting in the separation of the overlapped peaks of PB and AB. It was found from the standard addition method being applied to barley leaves that the GB content in plants could be evaluated by using a calibration curve of the GB standard solution. The extraction of GB from plant leaves was also improved by adopting water as the extraction solvent instead of a mixture of organic solvents. The present method was suitably applied to actual plant specimens collected from a saline area of China.     

A separation carrier in high-speed proteome analysis by capillary electrophoresis.

We obtained a high-efficiency separation carrier for proteome analysis by capillary electrophoresis. The addition of curdlan or laminaran to the run buffer hastened the migration time without any degradation in resolution. We propose that for the development of the separation carrier it is necessary to synthetically analyze each of the following mobility factors of electroosmotic flow: buffer ionic strength, additional disturbance and adsorption. The total analysis for buffer and additive will be useful for designing high-throughput screening (HTS) systems for proteome analysis without annoying adsorption.     

Recent advances in the analysis of antibiotics by capillary electrophoresis

In this review, the main aspects related to the separation of different groups of antibiotics by CE as well as the different applications reported in the literature from the beginning 2003 till May 2005 will be provided to the readers. Firstly, the experimental conditions employed to achieve the analysis of antibiotics by CE are given. Then, the main applications performed in the pharmaceutical, clinical, food, and environmental fields have been reviewed making emphasis on sample preparation requirements needed in each case. Finally, the main conclusions and future prospects in this field are presented.     

Recent progress in DNA analysis by capillary electrophoresis

A number of recent developments in DNA analysis by capillary electrophoresis are here reviewed. They include capillary arrays for fast, parallel DNA sequencing as well as microfabricated capillary arrays. Microfluidic chips for DNA sizing and quantitation are also covered, as well as microdevices containing arrays of regular obstacles acting as size-separators during DNA migration. Screening of DNA point mutations by two much improved techniques is also reported: in one case, such mutations are detected (but only on relative short, ca. 60-70 base-long fragments) by free electrophoresis in rather acidic (pH ca. 3) buffers; in the case of single-strand chain polymorphism, an improved technique is described based on near-neutral pH buffers with mixtures of Tris/MES cations/zwitterions. When studying the behavior of inorganic and organic cations in the Debye-Hückel layer of DNA, it was found that the latter (especially a large number of Good's buffers and other zwitterions, such as His) would bind to the DNA filament not only via charge interaction, but also via additional bonds, notably hydrogen bonds, thus altering the electrophoretic (and possibly the biological) behavior of DNA molecules. However, whether or not borate ions would bind to DNA remains still an unsettled question. Finally, capillary electrophoresis was found to be instrumental in measuring fine physicochemical parameters pertaining to DNA polyelectrolytes, such as their free mobility and their translational diffusion coefficients.     

毛细管电泳技术在重大疾病特异性蛋白质分析中的应用

人类重大疾病特异性蛋白质的识别、鉴定等是目前生命科学亟待解决的问题。毛细管电泳技术用于蛋白质分析,具有装置简单、分析速度快、试剂和样品消耗少以及有多种分离模式和检测手段等特点。本文综述了毛细管电泳技术在人类重大疾病特异性蛋白质分析中的应用,包括肿瘤疾病、神经退行性疾病和输血性传染病等的特异性蛋白质检测。