title: Labeling and intracellular tracking of functionally active plasmid DNA with semiconductor quantum dots.
abstract: Semiconductor nanocrystal quantum dots (QDs) allow long-term imaging in the cellular environment with high photostability. QD biolabeling techniques have previously been developed for tagging proteins and peptides as well as oligonucleotides. In this contribution, QD-decorated plasmid DNA was utilized for the first time for long-term intracellular and intranuclear tracking studies. Conjugation of plasmid DNA with phospholipid-coated QDs was accomplished using a peptide nucleic acid (PNA)-N-succinimidyl-3-(2-pyridylthio) propionate linker. Gel electrophoresis and confocal and atomic force microscopy (AFM) were used to confirm the structure of QD-DNA conjugates. AFM imaging also revealed that multiple QDs were attached in a cluster at the PNA-reactive site of the plasmid DNA. These QD-DNA conjugates were capable of expressing the reporter protein, enhanced green fluorescent protein, following transfection in Chinese hamster ovary (CHO-K1) cells with an efficiency of ca. 62%, which was comparable to the control (unconjugated) plasmid DNA.
authors.affiliation: Department of Pharmaceutical Sciences, University of Connecticut, 69 North Eagleville Road, Unit 3092, Storrs, 06269, USA.
authors.forename: Charudharshini
authors.initials: C
authors.lastname: Srinivasan
authors.forename: Jeunghoon
authors.initials: J
authors.lastname: Lee
authors.forename: Fotios
authors.initials: F
authors.lastname: Papadimitrakopoulos
authors.forename: Lawrence K
authors.initials: LK
authors.lastname: Silbart
authors.forename: Minhua
authors.initials: M
authors.lastname: Zhao
authors.forename: Diane J
authors.initials: DJ
authors.lastname: Burgess
mesh_terms: D000818:Animals; D016466:CHO Cells; D019187:Cadmium Compounds; D006224:Cricetinae; D004247:DNA / Q000378:metabolism* / Q000648:ultrastructure; D008823:Micelles; D018625:Microscopy, Atomic Force; D018613:Microscopy, Confocal; D015335:Molecular Probes; D020135:Peptide Nucleic Acids / Q000378:metabolism*; D010743:Phospholipids; D010957:Plasmids; D045663:Quantum Dots; D018036:Selenium Compounds; D013440:Sulfides; D014162:Transfection; D017967:Zinc Compounds
chemical_list: D019187:Cadmium Compounds; D008823:Micelles; D015335:Molecular Probes; D020135:Peptide Nucleic Acids; D010743:Phospholipids; D018036:Selenium Compounds; D013440:Sulfides; D017967:Zinc Compounds; D004247:DNA; C058667:cadmium selenide; C031238:zinc sulfide