title: Quantitative characterization of quantum dot-labeled lambda phage for Escherichia coli detection.
abstract: We characterize CdSe/ZnS quantum dot (QD) binding to genetically modified bacteriophage as a model for bacterial detection. Interactions among QDs, lambda (lambda) phage, and Escherichia coli are examined by several cross-validated methods. Flow and image-based cytometry clarify fluorescent labeling of bacteria, with image-based cytometry additionally reporting the number of decorated phage bound to cells. Transmission electron microscopy, image-based cytometry, and electrospray differential mobility analysis allow quantization of QDs attached to each phage (4-17 QDs) and show that lambda phage used in this study exhibits enhanced QD binding to the capsid by nearly a factor of four compared to bacteriophage T7. Additionally, the characterization methodology presented can be applied to the quantitative characterization of other fluorescent nanocrystal-biological conjugates.
authors.affiliation: National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA.
authors.forename: Peter B
authors.initials: PB
authors.lastname: Yim
authors.forename: Matthew L
authors.initials: ML
authors.lastname: Clarke
authors.forename: Michael
authors.initials: M
authors.lastname: McKinstry
authors.forename: Silvia H
authors.initials: SH
authors.lastname: De Paoli Lacerda
authors.forename: Leonard F
authors.initials: LF
authors.lastname: Pease
authors.forename: Marina A
authors.initials: MA
authors.lastname: Dobrovolskaia
authors.forename: HyeongGon
authors.initials: H
authors.lastname: Kang
authors.forename: Timothy D
authors.initials: TD
authors.lastname: Read
authors.forename: Shanmuga
authors.initials: S
authors.lastname: Sozhamannan
authors.forename: Jeeseong
authors.initials: J
authors.lastname: Hwang
mesh_terms: D000595:Amino Acid Sequence; D010582:Bacteriophage lambda / Q000378:metabolism* / Q000502:physiology*; D001483:Base Sequence; D036022:Capsid Proteins / Q000378:metabolism; D004926:Escherichia coli / Q000302:isolation & purification* / Q000821:virology; D005434:Flow Cytometry; D005453:Fluorescence; D046529:Microscopy, Electron, Transmission; D008969:Molecular Sequence Data; D045663:Quantum Dots; D013194:Staining and Labeling / Q000379:methods*; D053585:Virus Attachment
chemical_list: D036022:Capsid Proteins