[Molecular Biology with Genetics]

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Molecular Biology with Genetics

One of the most widely utilised analytical tools in molecular biology and disease diagnosis is the procedure and methods of electrophoresis. The principle of this procedure is that “electrophoresis is the migration of electrically charged particles or ions in solutions due to an applied electric field”1. The ability to separate substances which are almost identical including different proteins for analysis has increased throughout the past 7 decades. This is contributed to the introduction of zone electrophoresis in paper and more recently in gels like polyacrylamide and agarose. Today the methods used in electrophoresis have increased our advances in biochemistry, molecular biology and studies and diagnosis of disease, for example cancer and it has also become an invaluable tool in forensic science as it can identify species and individuals1 (2, 2005,, 24).

All though it was in 1791 when Faraday first presented his laws of electrolysis due to his experiments he formulated the theories of electrophoresis1. It was this procedure which was first pioneered in 1930 by a medical student working under Svedberg who had received the Nobel Prize for his own work on ultracentrifugation on proteins. The students name was Arne Wilhelm Kaurin Tiselius and it was then he published his thesis “Moving Boundary Electrophoresis” 2. He performed his experiments in a quartz U-tube using ultra violet light to photograph protein boundaries. However boundaries were often blurred in appearance caused by the heat in the solution, therefore results were not entirely accurate. It was not until 1937 he invented an electrophoresis apparatus which made it possible to obtain a much higher resolution and separation of charged molecules. The first of his experiments which were carried out with horse serum enabled the globulins to separate into three parts. Tiselius named the three parts alpha, beta, and gamma. Further investigation showed that the three areas were different chemically and that the antibodies, or immunoglobulins, were found in the gamma globulin or between the beta and gamma globulins3. Along with these set of experiments and the method he invented combined made moving boundary electrophoresis an accurate analytical method. All experiments and studies of this nature throughout the 1940s and 1950s were carried out using “Tiselius”-type apparatus equipped with Schlieren optics to visualize nucleic acid separations4 (5, 2004,, 1).

The SDS-PAGE has proved to be an important and valuable tool for the analysis and isolation of membrane proteins. This electrophoretic method is the most widely used in biomedical laboratories today. Estimation of protein size, assessment of the proteins purity, quantitation of proteins, monitor protein integrity, comparing composition of different samples, analysis of number and size of polypeptides, and for western blotting and also has a 2D capability. Throughout the 1970s techniques were changing and concepts of isotachophoresis and isoelectric focusing were being introduced, though the main aim throughout this decade was to find a way of miniaturising the equipment for analysis of certain biological samples4. Though this concept of smaller materials and the use of thin capillary like tubes was first ...