INTRINSIC ISOTACHOPHORETIC PRECONCENTRATION IN CAPILLARY GEL-ELECTROPHORESIS OF DNA RESTRICTION FRAGMENTS

Reproducible migration times are required for accurate base-pair assig nment of polymerase chain reaction (PCR) products in capillary gel ele ctrophoresis (CGE). However, migration times are influenced by injecti on plug length and ionic strength of the sample. In this paper we intr oduce a new isotachophoresis (ITP)-CGE system where the transition fro m ITP to CGE is achieved by the mobility shift of DNA from free soluti on (ITP) to sieving gel buffer (CGE). With intrinsic isotachophoretic preconcentration in capillary gel electrophoresis (IICGE) large volume injections (up to 700 nl) are possible with accurate migration times in CGE independent of injection plug length or sample ionic strength.