Visualization of Gene Transfer into Live Cells Using Fluorescent Semiconductor Nanocrystals

  • 김중경 ((주)디지탈바이오테크놀러지) ;
  • 임선희 ((주)디지탈바이오테크놀러지) ;
  • 이용구 (서울대학교 기계항공공학부) ;
  • 신영식 (서울대학교 기계항공공학부) ;
  • 정찬일 ((주)디지탈바이오테크놀러지) ;
  • 장준근 ((주)디지탈바이오테크놀러지, 서울대학교 전기컴퓨터공학부) ;
  • 유정열 (서울대학교 기계항공공학부)
  • Published : 2003.11.01


We have developed the method for the conjugation of biotinylated DNA to streptavidin-coated QDs. QD-DNA conjugates and a high-sensitive fluorescence imaging technique are adopted to visualize gene transport across the membrane of the live cell in real time. Endocytotic cellular uptake of oligonucleotide and electrically-mediated plasmid DNA transfer into the live cell are monitored by a quantitative microscopic imaging system. Long-term kinetic study enables us to reveal the unknown mechanisms and rate-limiting steps of extracellular and intracellular transport of biomolecules. We designed experimental protocols to conjugate the oligonucleotide or the plasmid DNA to commercially available streptavidin-coated QDs. Gel electrophoresis is used to verify the effect of incubation time and the molar ratio of QDs and DNA on the conjugation efficiency. It is possible to fractionate the QD-DNA conjugates according to the DNA concentration and obtain the purified conjugates by a gel extraction technique.