(1)Carl Gustav Carus University TU Dresden, Dresden, Germany. Usually proteins are separated by polyacrylamide gel electrophoresis (PAGE) in the presence. for native polyacrylamide gel electrophoresis. (native PAGE) with PhastGel™ gradient 8–25 and. PhastGel gradient Principle of the method. At the start of the. Proteins run on PAGE in the absence of SDS will separate on the basis of their charge to mass ratio. While native (nondenaturing) PAGE does not provide direct.


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Ferguson plot showing three proteins of the same charge but different native page principle. Ferguson plot showing three proteins of the same mass but different charge. As proteins migrate through the increasing acrylamide concentration, into regions of ever smaller pore sizes, their mobility decreases.

  • Native polyacrylamide gels.
  • Native Protein Electrophoresis | National Diagnostics
  • Alliance Protein Laboratories|Biophysical Characterization Services | Native gel electrophoresis

Eventually, each protein reaches its "pore-limit", at which point it slows to a minimum migration rate, which is constant for all proteins at their pore limit. The band pattern is stabilized at this native page principle, so that gradient native gel PAGE approaches an equilibrium system, in that beyond a certain run length only minimal changes occur in the gel pattern.

This occurs in a region of the gel that has larger pores so that the gel matrix does not retard the migration during the focusing or native page principle event.

The resolving gel typically native page principle a much smaller pore size, which leads to a sieving effect that now determines the electrophoretic mobility of the proteins. At the same time, the separating part of the gel also has a pH value in which the buffer ions on average carry a greater charge, causing them to "outrun" the SDS-covered proteins and eliminate the ion gradient and thereby the stacking effect.

A very widespread discontinuous buffer system is the tris-glycine or " Laemmli " system that stacks at a pH of 6.

A drawback of this system is that these pH values may promote disulfide bond formation between cysteine residues in the proteins because the pKa of cysteine ranges from and because reducing agent present in the loading buffer doesn't co-migrate with native page principle proteins.

Recent advances in buffering technology alleviate this problem by resolving the proteins at a pH well below the pKa of cysteine e.

An additional benefit of using buffers with native page principle pH values is that the acrylamide gel is more stable at lower pH values, so the gels can be stored for long periods of time before use.

Gel electrophoresis of proteins

Friedrich Kohlrausch found that Ohm's law also applies to dissolved electrolytes. Do not adjust the pH. Prepare appropriate amount of separating gel in a small beaker, then add specific native page principle.


The three-dimensional molecular network comes into being by a radical polymerisation of acrylamide monomers and cross-linking N,N'-methylenebisacrylamide components.

Without native page principle modification, polyacrylamide electrophoresis separates macromolecular ions based on a combination of charge, size and shape.


Size and shape separation is due to the molecular sieving property of the gel. The size range in which molecules can be separated is dictated by the average pore size of the gel. In the case of polyacrylamide gels, this can be controlled through the concentration of the acrylamide monomer and the proportion of native page principle cross-linking N,N'-methylenebisacrylamide.

Polyacrylamide gel electrophoresis (PAGE)

Below this range the gel will be too soft and it will not keep its shape, while above this range it will be too rigid and prone to break. The polyacrylamide native page principle possesses all advantageous properties necessary for a good electrophoresis medium, i.

A further very important property of the polyacrylamide gel is that it does not participate in any non-specific or specific binding interaction with proteins. Furthermore, the polyacrylamide gel does not interfere with common protein staining reactions.

When electrophoresis is performed under native non-denaturing native page principle, such as near neutral pH and ambient or lower native page principle, many enzymes retain their native conformation and, in turn, their enzymatic activity.

This way, many enzymes can be separated and specifically detected in the gel after electrophoretic separation. Radical polymerisation is subsequently triggered by suitable catalyst and initiator compounds.

Native polyacrylamide gels.

The catalyst is usually ammonium persulfate, which spontaneously decomposes in aqueous media, thereby generating free radicals. These free radicals in themselves cannot efficiently cleave the double bonds of the acrylamide molecule, but are able to excite the electrons of the initiator molecules.

This leads to the generation of free radicals, originating from the initiator molecules, that are able to trigger radical polymerisation of acrylamide monomers. There are two types of gels native page principle to their geometry. In early gel electrophoretic applications, gel tubes were used that native page principle only a single sample to be run.

Gel slabs were later introduced, allowing for many samples to be run at the same time in the same gel in parallel.

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