For larger molecules like proteins we use polyacrylamide gel electrophoresis (PAGE). For smaller pieces like DNA we use agarose gel electrophoresis

it is used in gel electrophoresis.....for the separation of DNA fragments

Hi,

I assume you mean gel electrophoresis of proteins (commonly done in a polyacrylamide gel e.g. SDS-PAGE) or agarose gel electrophoresis of DNA.

Generally, as electrophoresis is allowed to proceed for a long time, the gel and the buffer in which it is submerged in becomes heated (due to Joule heating effects of the current supply). The heating causes the pores in the gel matrix to lose their definition (due to flaccidness induced upon the polyacrylamide / agarose matrix strands within the gel) and the sample molecules (being electrophoresed) can now easily 'force' their way through the meshwork of fibres within the gel, thus creating an illusionary aspect of 'enhanced rate of migration' (i.e. 'increased rate of electrophoresis').

Hope this answers your query.

Thanks and Regards,

Shiraz

The process is referred to as gel electrophoresis.

This is an analytical process where DNA fragments can be separated based on size within a gel under the influence of an electric field