Английская Википедия:Discontinuous electrophoresis

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Шаблон:Short description

Файл:Gel electrophoresis 2.jpg
DNA bands after electrophoresis

Discontinuous electrophoresis (colloquially disc electrophoresisШаблон:Efn) is a type of polyacrylamide gel electrophoresis. It was developed by Ornstein and Davis.[1][2] This method produces high resolution and good band definition. It is widely used technique for separating proteins according to size and charge.[3]

Method

In this method, the gel is divided into two discontinuous parts, resolving and stacking gel, both have different concentrations of polyacrylamide.[4] The one with lower concentration is stacked on top of the one with higher concentration. Discontinuity is based on four parameters: gel structure, pH value of the buffer, ionic strength of the buffer, and the nature of the ions in the gel and electrode buffer. The electrode buffer contains glycine. Glycine has very low net charge at pH 6.8 of stacking gel, so it has low mobility. The proteins are separated according to the principle of isotachophoresis and form stacks in the order of mobility (stacking effect). Mobility depends on net charge, not on the size of the molecule. Proteins move towards anode slowly at constant speed till they reach limit of separation gel. Suddenly, frictional resistance increases but glycine is not affected and it passes the proteins and becomes highly charged in resolving zone. Proteins present in homogeneous buffer start to separate based on principles of zone electrophoresis. Now their mobility depends on size as well as charge. pH value rises to 9.5 and net charge increases.[5][6]

See also

References

Шаблон:Reflist Шаблон:Notelist

External links

Шаблон:Electrophoresis

  1. Шаблон:Cite journal
  2. Шаблон:Cite journal
  3. Шаблон:Cite book
  4. Шаблон:Cite web
  5. Disc Electrophoresis and Related Techniques of Polyacrylamide Gel Electrophoresis Author H. R. Maurer Edition 2, illustrated Publisher Walter de Gruyter, 1978 Шаблон:ISBN, 9783110836202
  6. Шаблон:Cite web