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The main basis in a SDS-PAGE electrophoresis is the gel preparation. Polyacrylamide gels, made of stacking and resolving gels, are well suited for protein electrophoresis due to wide range of pore sizes which are suitable for sieving proteins as well as confering the easiness of polymerization reaction, the possibility of altering the pore size by monomer concentration,being hydrophilic and electrically neutral at the time they are cast and finally transparent to light at wavelengths above about 250 nm and do not bind protein stains (AES Electrophoresis Society, ?). Gels that are formed from acrylamide monomers are polymerized into long chains by bis molecules; this can form a structure of a mass of relatively rigid network spaces of fibers that have both solid and liquid components. This network helps maintain the buffer in the gel to uphold the gel’s three-dimensional shape. In the structure of polyacrylamide gels, the use of chemical system is to form the polymerization (free radicals) consists of ammonium persulfate (APS) as an initiator peroxide and N,N,N’,N’-tetramethylethylenediamine (TEMED) as the catalyst (Kavoosi & Ardestani, 2012).According to Davey and Lord (2003), TEMED facilitate the breakdown of persulfate molecules into sulfate free radicals and this leads to the polymerization process. The polymerization is most efficient at alkaline pH(>6) due to the compulsory presence of the free base of TEMED as required for this reaction.

Polyacrylamide gels are featured by values of %T and %C which are the weight percentage of total monomer (acrylamide + bis) in g/100 ml and the proportion of bis as a percentage of total monomer respectivly. In protein electrophoresis, the pores of the gel are of main importance. The effec...

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...he mobilities of test proteins to the mobilities of known protein marker(also known as protein ladder/lane)with measured molecular masses. The migration distances are measured from the top of the resolving gel since tube gels are different in length. Rf, the normalizing parameter is the value used in SDS-PAGE analysis and is defined as the mobility of a protein (in migrated distance) divided by the mobility of the ion front (tracking dye) in a specific gel run time so that the different length of tube gels could be estimated and the desired protein could be tracked. The standard sigmoid plot of the logarithm of protein molecular mass (log MW) versus the migration distances Relative Mobility (Rf) forms reasonably straight lines. Introduction of the migration distances of test proteins into the standard curve gives the approximate molecular masses of the test proteins.
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