Sigma factor Region 2.3 is responsible for melting the DNA at -10 element.

#Id: 2458

#Unit 13. Methods in Biology

When the potential gradient E is applied, the force F on a molecule bearing a charge of Q  sepreated  by distance d (measured in coulombs) is                  (in newton). 

#Id: 2459

#Unit 13. Methods in Biology

If the frictional force taken into the consideration (which depend on hydrodynamic size, shape of the molecule, pore size of the medium, & pore size of the medium) velocity, v , of a charged molecule in an electric field is therefore given by the equation

where f is the frictional coefficient.

#Id: 2460

#Unit 13. Methods in Biology

During electrophoresis generation of heat is the major problem which leads to

ncreased rate of diffusion of sample and buffer ions.

Thermal instability which include denaturation of proteins.

A decrease of buffer viscosity.

Convection current leads mixing of separated samples

#Id: 2461

#Unit 13. Methods in Biology

Electrophoresis can be performed in two environment 

In free solution - Moving boundary electrophoresis (A. G. Tiselius) & CE

n the medium  -  GEL ( Agarose & PAGE )

#Id: 2462

#Unit 13. Methods in Biology

A. G. Tiselius (1937) Performed Moving boundary electrophoresis  in a U-shaped tube using Schlieren optics on both end for Measurements of the electrophoretic mobilities.

#Id: 2463

#Unit 13. Methods in Biology

He received Nobel Prize in 1948 for developing technique for electrophoretic separation of substances.