2. Nucleic acid analysis techniques: basic tools

2.1 Electrophoresis

Nucleic acids are charged polyanionic macromolecules that can migrate in an electric field. Electrophoresis enables DNA fragments or RNA molecules to be separated according to their molecular weight, i.e. the number of bases or base pairs, with varying degrees of resolution depending on the nature and cross-linking density of the gel used. Two types of gel exist: agarose and polyacrylamide. Depending on the size of the product to be examined, the concentration of agarose or acrylamide to be used will differ (table 1 ).

Polyacrylamide gel is used for the separation of small DNA fragments of one to several hundred base pairs (bp). Its main applications are the separation of small DNA...