Quantitative characterization of quantum dot-labeled lambda phage for Escherichia coli detection.
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.
Yim
Peter B
PB
National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA.
Clarke
Matthew L
ML
McKinstry
Michael
M
De Paoli Lacerda
Silvia H
SH
Pease
Leonard F
LF
Dobrovolskaia
Marina A
MA
Kang
HyeongGon
H
Read
Timothy D
TD
Sozhamannan
Shanmuga
S
Hwang
Jeeseong
J
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
D036022:Capsid Proteins