Improved method for the removal of endotoxin from DNA.

Contaminating endotoxin in solutions used in gene therapy and genetic immunization can result in various deleterious effects both in vitro and in vivo. In order to avoid such complications, attempts were made to characterize the extent of the problem of endotoxin contamination and develop a solution to this problem. After screening for endotoxin in plasmid DNA preparations using the Limulus Amoebocyte Lysate (LAL) assay, nearly half of all samples displayed high endotoxin levels. Therefore, a simple one-step procedure was developed for the removal of endotoxin using a polymyxin B resin.