title: A method to increase the bioactivity of plasmid DNA by heat treatment.
abstract: A method to increase the bioactivity of plasmid DNA by heat treatment has been developed. The structure of the heat treated plasmid DNA was investigated by electrophoresis assay and atomic force microscope (AFM) observation. Electrophoresis assay showed that the heat treated DNA consisted of three components: the supercoiled DNA (component I), the open circular DNA (component II) and the heat denatured DNA component. The bioactivity of the heat treated plasmid DNA was investigated by both DNA condensation experiments and gene transfection experiment with mammal cells. DNA condensation experiments showed that the heat denatured DNA component owned higher sensitivity to spermidine and polyethylenimine (PEI) than component I and component II DNA. Gene transfection experiment with PEI indicated that the heat treated DNA had higher gene transfection efficiency than untreated DNA. Our experiment not only shows an effective approach to increase the bioactivity of plasmid DNA but also leads a way to improve the bioactivity of DNA by physically modifying their structure.
authors.affiliation: College of Life Science, Nankai University, Tianjin 300071, PR China.
authors.forename: Sen
authors.initials: S
authors.lastname: Hou
authors.forename: Kun
authors.initials: K
authors.lastname: Yang
authors.forename: Ze
authors.initials: Z
authors.lastname: Liu
authors.forename: Xi-Zeng
authors.initials: XZ
authors.lastname: Feng
mesh_terms: D002460:Cell Line; D004247:DNA / Q000032:analysis* / Q000737:chemistry / Q000235:genetics* / Q000648:ultrastructure; D004587:Electrophoresis, Agar Gel; D004926:Escherichia coli / Q000235:genetics; D006358:Hot Temperature; D006801:Humans; D018625:Microscopy, Atomic Force; D009691:Nucleic Acid Denaturation / Q000187:drug effects; D010957:Plasmids / Q000032:analysis* / Q000737:chemistry / Q000235:genetics* / Q000648:ultrastructure; D011094:Polyethyleneimine / Q000494:pharmacology; D013095:Spermidine / Q000494:pharmacology; D014162:Transfection
chemical_list: D011094:Polyethyleneimine; D004247:DNA; D013095:Spermidine