Displaying publications 1 - 20 of 658 in total

  1. Ch'ng SL, Chandrasekharan N
    Family Practitioner, 1987;10<I> </I>:12-13.
    Matched MeSH terms: Electrophoresis
  2. Abd Rahman N, Ibrahim F, Yafouz B
    Sensors (Basel), 2017 Feb 24;17(3).
    PMID: 28245552 DOI: 10.3390/s17030449
    Dielectrophoresis (DEP) is a label-free, accurate, fast, low-cost diagnostic technique that uses the principles of polarization and the motion of bioparticles in applied electric fields. This technique has been proven to be beneficial in various fields, including environmental research, polymer research, biosensors, microfluidics, medicine and diagnostics. Biomedical science research is one of the major research areas that could potentially benefit from DEP technology for diverse applications. Nevertheless, many medical science research investigations have yet to benefit from the possibilities offered by DEP. This paper critically reviews the fundamentals, recent progress, current challenges, future directions and potential applications of research investigations in the medical sciences utilizing DEP technique. This review will also act as a guide and reference for medical researchers and scientists to explore and utilize the DEP technique in their research fields.
    Matched MeSH terms: Electrophoresis*
  3. John AS, Sidek MM, Thang LY, Sami S, Tey HY, See HH
    J Chromatogr A, 2021 Feb 08;1638:461868.
    PMID: 33453653 DOI: 10.1016/j.chroma.2020.461868
    One of the major drawbacks of electrophoresis in both capillary and microchip is the unsatisfactory sensitivity. Online sample preconcentration techniques can be regarded as the most common and powerful approaches commonly applied to enhance overall detection sensitivity. While the advances of various online preconcentration strategies in capillary and microchip employing aqueous background electrolytes are well-reviewed, there has been limited discussion of the feasible preconcentration techniques specifically developed for capillary and microchip using nonaqueous background electrolytes. This review provides the first consolidated overview of various online preconcentration techniques in nonaqueous capillary and microchip electrophoresis, covering the period of the last two decades. It covers developments in the field of sample stacking, isotachophoresis, and micellar-based stacking. Attention is also given to multi-stacking strategies that have been used for nonaqueous electrophoresis.
    Matched MeSH terms: Electrophoresis, Capillary/methods*; Electrophoresis, Microchip/methods*
  4. Sthaneshwar P, Thambiah SC, Mat Salleh MJ, Nasuruddin DN, Ahmad Zabidi NF, Jelani AM, et al.
    Malays J Pathol, 2021 Aug;43(2):281-290.
    PMID: 34448792
    INTRODUCTION: Serum protein electrophoresis (SPE) is a well-established laboratory technique. However, reporting of results varies considerably between laboratories. The variation in reporting can cause confusion to the clinician with a potential of adversely impacting patient care. The purpose of the survey was to find out the variation in reporting and to prepare recommendations to the Malaysian laboratories based on the survey to reduce both the variation in reporting between laboratories and the risk of misinterpretation of reports.

    MATERIALS AND METHODS: To determine the extent of variation in reporting of protein electrophoresis results questionnaires were distributed to the pathologists of various laboratories in Malaysia regarding the method, quantification of paraprotein concentrations and immunoglobulin assays, and information regarding current laboratory electrophoresis practices.

    RESULTS: Variation was found in the following reporting practices: (a) screening protocol; (b) reporting of serum albumin; (c) numerical reporting of protein fractions and paraprotein; (d) co-migration of a paraprotein with a normal serum protein; (e) reporting of multiple paraprotein bands (f) appearance of small abnormal band and oligoclonal bands and (g) communication about of interferences.

    CONCLUSION: The pathologists of the country made recommendations on the reporting of protein electrophoresis. Harmonised reporting will reduce inconsistency, variation in reporting, improve the quality of the report and most importantly improve patient care.

    Matched MeSH terms: Electrophoresis*
  5. Ghanim MH, Najimudin N, Ibrahim K, Abdullah MZ
    IET Nanobiotechnol, 2014 Jun;8(2):77-82.
    PMID: 25014078 DOI: 10.1049/iet-nbt.2012.0044
    Miniaturisation of microchip capillary electrophoresis (MCE) is becoming an increasingly important research topic, particularly in areas related to micro total analysis systems or lab on a chip. One of the important features associated with the miniaturised MCE system is the portable power supply unit. In this work, a very low electric field MCE utilising an amperometric detection scheme was designed for use in DNA separation. The device was fabricated from a glass/polydimethylsiloxane hybrid engraved microchannel with platinum electrodes sputtered onto a glass substrate. Measurement was based on a three-electrode arrangement, and separation was achieved using a very low electric field of 12 V/cm and sample volume of 1.5 µl. The device was tested using two commercial DNA markers of different base pair sizes. The results are in agreement with conventional electrophoresis, but with improved resolution. The sensitivity consistently higher than 100 nA, and the separation time approximately 45 min, making this microchip an ideal tool for DNA analysis.
    Matched MeSH terms: Electrophoresis, Agar Gel/instrumentation; Electrophoresis, Agar Gel/methods; Electrophoresis, Capillary/instrumentation; Electrophoresis, Capillary/methods*; Electrophoresis, Microchip/instrumentation; Electrophoresis, Microchip/methods*
  6. Seng TY, Singh R, Faridah QZ, Tan SG, Alwee SS
    Genet. Mol. Res., 2013;12(3):2360-7.
    PMID: 23546970 DOI: 10.4238/2013.March.11.1
    Genetic markers are now routinely used in a wide range of applications, from forensic DNA analysis to marker-assisted plant and animal breeding. The usual practice in such work is to extract the DNA, prime the markers of interest, and sift them out by electrically driving them through an appropriate matrix, usually a gel. The gels, made from polyacrylamide or agarose, are of high cost, limiting their greater applications in molecular marker work, especially in developing countries where such technology has great potential. Trials using superfine resolution (SFR) agarose for SSR marker screening showed that it is capable of resolving SSR loci and can be reused up to 14 times, thus greatly reducing the cost of each gel run. Furthermore, for certain applications, low concentrations of agarose sufficed and switching to lithium borate buffer, instead of the conventional Tris-borate-ethylenediaminetetraacetic acid buffer, will further save time and cost. The 2.5% gel was prepared following the Agarose SFR(TM) manual by adding 2.5 g agarose powder into 100 mL 1X lithium borate buffer in a 250-mL flask with rapid stirring. Two midigels (105 x 83 mm, 17 wells) or 4 minigels (50 x 83 mm, 8 wells), 4 mm thickness can be prepared from 100 mL gel solution. A total of 1680 PCR products amplified using 140 SSR markers from oil palm DNA samples were tested in this study using SFR recycled gel. As average, the gel can be recycled 8 times with good resolution, but can be recycled up to 14 times before the resolutions get blurred.
    Matched MeSH terms: Electrophoresis, Agar Gel/methods*
  7. VELLA F
    Med J Malaya, 1959 Sep;14:31-5.
    PMID: 13855207
    Matched MeSH terms: Electrophoresis*
  8. Kee PE, Lan JC, Yim HS, Tan JS, Chow YH, Ng HS
    Appl Biochem Biotechnol, 2020 May;191(1):376-386.
    PMID: 31907777 DOI: 10.1007/s12010-019-03202-y
    Cytochrome c is a small water-soluble protein that is abundantly found in the mitochondrial intermembrane space of microorganism, plants and mammalians. Ionic liquids (ILs)-based aqueous two-phase electrophoresis system (ATPES) was introduced in this study to investigate the partition efficiency of cytochrome c to facilitate subsequent development of two-phase electrophoresis for the separation of cytochrome c from microbial fermentation. The 1-Hexyl-3-methylimidazolium bromide, (C6mim)Br and potassium citrate salt were selected as the phase-forming components. Effects of phase composition; position of electrodes; pH and addition of neutral salt on the partition efficiency of cytochrome c in the ATPES were evaluated. Highest partition coefficient (K = 179.12 ± 0.82) and yield of cytochrome c in top phase (YT = 99.63% ± 0.00) were recorded with IL/salt ATPES composed of 30% (w/w) (C6mim)Br and 20% (w/w) potassium citrate salt of pH 7 and 3.0% (w/w) NaCl addition with anode at the bottom phase and cathode at the top phase. The SDS-PAGE profile revealed that cytochrome c with a molecular weight of 12 kDa was preferably partitioned to the IL-rich top phase. Present findings suggested that the single-step ATPES is a potential separation approach for the recovery of cytochrome c from microbial fermentation. Graphical Abstract.
    Matched MeSH terms: Electrophoresis*
  9. Lee PY, Saraygord-Afshari N, Low TY
    J Chromatogr A, 2020 Mar 29;1615:460763.
    PMID: 31836310 DOI: 10.1016/j.chroma.2019.460763
    Two-dimensional gel electrophoresis (2-DE) is a technique that has been widely applied in a variety of proteomics studies. It is capable of resolving complex protein mixtures into individual protein spots based on their isoelectric point and molecular weight, enabling large-scale analysis of protein expression patterns for deciphering their changes in different biological conditions. 2-DE is a powerful tool that empowers researchers to perform differential qualitative and quantitative proteome analysis and is particularly advantageous for characterizing protein isoforms and post-translationally modified proteins. Despite its popularity as the workhorse for proteomics in the past few decades, it has been gradually displaced by the more sophisticated and high-performance mass spectrometry-based methods. However, there are several variations of the 2-DE technique that have emerged as promising approaches that shine new light on specific niches that 2-DE could still contribute. In this review, we first provide an overview of the applications of 2-DE, its merits and pitfalls in the current proteomic research arena, followed by a discussion on several alternative approaches for potential future applications.
    Matched MeSH terms: Electrophoresis, Polyacrylamide Gel/trends; Electrophoresis, Gel, Two-Dimensional/history; Electrophoresis, Gel, Two-Dimensional/trends*
  10. Yafouz B, Kadri NA, Ibrahim F
    Sensors (Basel), 2014;14(4):6356-69.
    PMID: 24705632 DOI: 10.3390/s140406356
    This paper introduces a dielectrophoretic system for the manipulation and separation of microparticles. The system is composed of five layers and utilizes microarray dot electrodes. We validated our system by conducting size-dependent manipulation and separation experiments on 1, 5 and 15 μm polystyrene particles. Our findings confirm the capability of the proposed device to rapidly and efficiently manipulate and separate microparticles of various dimensions, utilizing positive and negative dielectrophoresis (DEP) effects. Larger size particles were repelled and concentrated in the center of the dot by negative DEP, while the smaller sizes were attracted and collected by the edge of the dot by positive DEP.
    Matched MeSH terms: Electrophoresis/instrumentation; Electrophoresis/methods*
  11. Ghanim MH, Abdullah MZ
    Talanta, 2011 Jul 15;85(1):28-34.
    PMID: 21645665 DOI: 10.1016/j.talanta.2011.04.069
    Recent advances in microfluidic systems, particularly in the Micro Total Analysis System (μTAS) or Lab On a Chip (LOC), drive the current analysis tools and equipment towards miniaturization, rapid at-line testing and mobility. The state-of-the-art microfluidic technology targets a wider range but smaller volumes of analytes, making the analytical procedure relatively easier and faster. This trend together with faster electronics and modern instrumentation systems will make real-time and in situ analysis a definite possibility. This review focuses on microchip capillary electrophoresis with amperometric detection (MCE-AD) for the detection of DNA and other electroactive analytes. The problems associated with the microchip design, in particular the choice of materials and the configuration of electrodes are discussed thoroughly and solutions are proposed. Significant developments in the related areas are also covered and reviewed critically.
    Matched MeSH terms: Electrophoresis, Microchip/methods*; Electrophoresis, Microchip/trends
  12. Heng SK, Heng CK, Puthucheary SD
    Indian J Med Microbiol, 2009 Apr-Jun;27(2):142-5.
    PMID: 19384038 DOI: 10.4103/0255-0857.49428
    Pulsed field gel electrophoresis (PFGE), the gold standard of molecular typing methods, has a major disadvantage of an unusually long electrophoretic time. From the original protocol of 6 days, it was modified to 3 days and subsequently to a single day. We describe the procedure of stacking five to six gels one on top of another in order to increase and maximize the output in a shorter time without compromising the resolution and reproducibility. All the variables that affect pulsed field gels during electrophoresis were taken into consideration. We firstly optimized the parameters to be used and secondly determined whether stacking of five to six gels had any effect on the molecular separation during electrophoresis in comparison with a single gel run. DNA preparation, restriction, electrophoresis, staining and gel documentation was carried out based on previously published methods. Gels were analysed using BioNumerics and dice coefficient and unweighted pair group methods were used to generate dendrograms based on 1.5% tolerance values. Identical band profiles and band resolution-separation were seen in the PFGE patterns with single gel and multiple stacking gels. Cluster analysis further strengthened the fact that results from stacking gels were reproducible and comparable with a single gel run. This method of stacking gels saves time and maximizes the output at the same time. The run time for a single gel was about 28 hours, but with six stacked gels the run time was 54 hours compared with 28 x 6 = 168 hours if they were run separately as single gels thus saving time of 67.86%. Beside the big factor of saving time, stacking gels save resources (electricity, reagents, water, chemicals and working time) by increasing the sample throughput in a shorter time without compromising on quality of data. But optimization of working parameters is vital depending on the PFGE system used.
    Matched MeSH terms: Electrophoresis, Gel, Pulsed-Field/economics; Electrophoresis, Gel, Pulsed-Field/methods
  13. Amid M, Abd Manap MY
    Food Chem, 2014 Dec 15;165:412-8.
    PMID: 25038694 DOI: 10.1016/j.foodchem.2014.03.133
    An amylase enzyme from pitaya peel was purified 234.2-folds with 72.1% recovery using ammonium sulphate precipitation, gel filtration and ion exchange chromatography. Gel filtration chromatography and SDS-PAGE revealed that the enzyme is monomeric with a molecular weight of 42.1kDa. The apparent Km and Vmax of the amylase were 2.7 mg/ml and 34.30 u/min/mg of protein, respectively. The enzyme was highly active and stable over a wide pH range from pH 3 to pH 11.0, with optimum activity being observed at pH 5.0. The enzyme was highly selective for soluble starch, amylopectin, glycogen and pulullan. The purified amylase did not require calcium and displayed extreme stability with regard to surfactants and oxidising agents. EDTA, a powerful chelating agent, did not have any significant effect on the stability of the enzyme. Such characteristics have not been previously reported for this type of enzyme from fruit peel. This enzyme, which possesses unique properties, could be widely used in different types of industries, especially in food and biotechnological applications.
    Matched MeSH terms: Electrophoresis, Polyacrylamide Gel/methods*
  14. Al Azzam KM, Saad B, Aboul-Enein HY
    Biomed Chromatogr, 2010 Sep;24(9):948-53.
    PMID: 20082285 DOI: 10.1002/bmc.1390
    Capillary zone electrophoresis coupled with a capacitively coupled contactless conductivity detector (CE-C(4)D) has been employed for the determination of atenolol and amiloride in pharmaceutical formulations. Acetic acid (150 mm) was used as background electrolyte. The influence of several factors (detector excitation voltage and frequency, buffer concentration, applied voltage, capillary temperature and injection time) was studied. Non-UV-absorbing L-valine was used as internal standard; the analytes were all separated in less than 7 min. The separation was carried out in normal polarity mode at 28 degrees C, 25 kV and using hydrodynamic injection (25 s). The separation was effected in an uncoated fused-silica capillary (75 microm, i.d. x 52 cm). The CE-C(4)D method was validated with respect to linearity, limit of detection and quantification, accuracy, precision and selectivity. Calibration curves were linear over the range 5-250 microg/mL for the studied analytes. The relative standard deviations of intra- and inter-day migration times and corrected peak areas were less than 6.0%. The method showed good precision and accuracy and was successfully applied to the simultaneous determination of atenolol and amiloride in different pharmaceutical tablet formulations.
    Matched MeSH terms: Electrophoresis, Capillary/methods*
  15. Lee SV, Bahaman AR
    Trop Biomed, 2010 Aug;27(2):351-4.
    PMID: 20962737
    Agarose gel electrophoresis is the standard method that is used to separate, identify, and purify DNA fragments. However, this method is time-consuming and capable of separating limited range of fragments. A new technique of gel preparation was developed to improve the DNA fragment analysis via electrophoresis.
    Matched MeSH terms: Electrophoresis, Agar Gel*
  16. Mohd Khalizan Sabullah, Azlan Jualang Gansau, Mohd Rosni Sulaiman, Fisal Ahmad
    Observations on the effects of copper on the liver proteome of Puntius javanicus based on the
    one dimensional PAGE was carried out. The liver was dissected from each fish, which was
    separately treated with different concentrations of copper sulfate ranging from 0.1 to 5.0 mg/L.
    The livers were extracted and one dimensional PAGE was performed under nonreducing
    (native) and reducing (SDS)-PAGE. Several bands were resolved in the native PAGE with
    probable candidates for the effect of copper observed showing an increased in the expression
    and downregulation strongly associated with increasing copper concentrations. This study
    showed that high concentrations of copper significantly alters P. javanicus liver at the proteome
    level, and preliminary screening based on one dimensional PAGE is considered rapid and
    simple to assess the toxicity effect of copper before more advanced and extensive assesment
    with a second dimensional PAGE is carried out.
    Matched MeSH terms: Electrophoresis, Polyacrylamide Gel; Native Polyacrylamide Gel Electrophoresis
  17. Yahaya N, Huang ZA, Yan B, Chen DDY
    Food Chem, 2022 Mar 15;372:131220.
    PMID: 34607048 DOI: 10.1016/j.foodchem.2021.131220
    A simple and sensitive method for the determination of bisphenol A and its analogues at the ng/mL level in bottled tea beverages is presented. This method utilized a dynamic pH junction to focus the analyte into a more concentrated zone, based on the electrophoretic mobility difference of analytes in the sample matrix and background electrolytes in capillary electrophoresis coupled to mass spectrometry (CE-MS). The optimised analyte focusing led to enhanced signal detection with average peak heights for five bisphenols of 53-170 folds higher than conventional injections. Under optimised conditions, the method showed good linearity in the range of 0.1-100 ng/mL, excellent limits of detection (0.03-0.04 ng/mL), good analyte recovery (80.3-118.1%) with acceptable relative standard deviations (<12%). The limits of quantifications were below the maximum permissible content of bisphenol A set by the European Commission for this product. This method was used to quantitatively analyse bisphenols in six different kinds of bottled tea beverages, making it a promising tool for practical applications.
    Matched MeSH terms: Electrophoresis, Capillary*
  18. Elbashir AA, Saad B, Ali AS, Saleh MI
    J AOAC Int, 2008 6 24;91(3):536-41.
    PMID: 18567298
    A capillary electrophoresis (CE) method has been developed that allows the separation and estimation of primaquine enantiomers using hydroxypropyl-gamma-cyclodextrin (HP-gamma -CD) as a chiral selector. The influence of chemical and instrumental parameters on the separation, such as type and concentration of CD, buffer concentration, buffer pH, applied voltage, capillary temperature, and injection time, were investigated. Good separation of the racemic mixture of primaquine was achieved using a fused-silica capillary (52.5 cm effective length x 50 microm id) and a background electrolyte composed of tris-phosphate buffer solution (50 mM, pH 2.5) containing 15 mM HP-gamma-CD as a chiral selector. The recommended applied voltage, capillary temperature, and injection time were 15 kV, 25 degrees C, and 6 s, respectively. Within-day and interday reproducibility of peak area and migration time gave relative standard deviation values ranging from 1.05-3.30%. Good recoveries (range of 96.8-104.9%) were obtained from the determination of placebos that were spiked with 0.25-1.00 mg/L primaquine. The proposed CE method was successfully applied to the assay of primaquine diphosphate in pharmaceutical formulations (tablets).
    Matched MeSH terms: Electrophoresis, Capillary/methods*; Electrophoresis, Capillary/standards; Electrophoresis, Capillary/statistics & numerical data
  19. Buyong MR, Larki F, Faiz MS, Hamzah AA, Yunas J, Majlis BY
    Sensors (Basel), 2015;15(5):10973-90.
    PMID: 25970255 DOI: 10.3390/s150510973
    In this work, the dielectrophoretic force (F(DEP)) response of Aluminium Microelectrode Arrays with tapered profile is investigated through experimental measurements and numerical simulations. A standard CMOS processing technique with a step for the formation of a tapered profile resist is implemented in the fabrication of Tapered Aluminium Microelectrode Arrays (TAMA). The F(DEP) is investigated through analysis of the Clausius-Mossotti factor (CMF) and cross-over frequency (f(xo)). The performance of TAMA with various side wall angles is compared to that of microelectrodes with a straight cut sidewall profile over a wide range of frequencies through FEM numerical simulations. Additionally, electric field measurement (EFM) is performed through scanning probe microscopy (SPM) in order to obtain the region of force focus in both platforms. Results showed that the tapered profile microelectrodes with angles between 60° and 70° produce the highest electric field gradient on the particles. Also, the region of the strongest electric field in TAMA is located at the bottom and top edge of microelectrode while the strongest electric field in microelectrodes with straight cut profile is found at the top corner of the microelectrode. The latter property of microelectrodes improves the probability of capturing/repelling the particles at the microelectrode's side wall.
    Matched MeSH terms: Electrophoresis
  20. Abdul Keyon AS, Miskam M, Ishak NS, Mahat NA, Mohamed Huri MA, Abdul Wahab R, et al.
    J Sep Sci, 2019 Feb;42(4):906-924.
    PMID: 30605233 DOI: 10.1002/jssc.201800859
    Depression is a common mental disorder that may lead to major mental health problems, and antidepressant drugs have been used as a treatment of choice to mitigate symptoms of major depressive disorders by ameliorating the chemical imbalances of neurotransmitters in brain. Since abusing antidepressant drugs such as selective serotonin reuptake inhibitors and tricyclic antidepressant drugs can cause severe adverse effects, continuous toxicological monitoring of the parent compounds as well as their metabolites using numerous analytical methods appears pertinent. Among them, capillary electrophoresis has been popularly utilized since the method has a lot of advantages viz. using small amounts of sample and solvents, ease of operation, and rapid analysis. This review paper brings a survey of more than 30 papers on capillary electrophoresis of antidepressant drugs published approximately from 1999 until 2018. It focuses on the reported capillary electrophoresis techniques and their applications and challenges for determining antidepressant drugs and their metabolites. It is organized according to the commonly used capillary zone electrophoresis method, followed by non-aqueous capillary electrophoresis and micellar electrokinetic chromatography, with details on breakthrough findings. Where available, information is given about the background electrolyte used, detector utilized, and sensitivity obtained.
    Matched MeSH terms: Electrophoresis, Capillary
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