Quantum dots as alternatives to organic fluorophores for Cryptosporidium detection using conventional flow cytometry and specific monoclonal antibodies: Lessons learned

B. C. Ferrari*, Peter Bergquist

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

32 Citations (Scopus)

Abstract

Background: Significant developments in biological applications are occurring through the incorporation of Quantum Dots (QDs) as biological labels. The demonstration of QDs unique optical properties may have important implications for the study of environmental samples, where microorganisms of interest need to be isolated away from the background debris.

Methods: Flow cytometric analysis was used to determine the fluorescence intensity of oocysts after mAb staining by QDs or organic fluorophore conjugates. In addition, the level of non-specific binding to detrital particles within a control water concentrate was estimated using the optimal staining concentration determined for each mAb analyzed.

Results: Under 488 nm excitation, cocysts stained with QD-conjugates exhibited significantly lower fluorescence intensity than organic conjugates. Moreover, the level of non-specific binding by QD-conjugates to detrital particles present in the water concentrate was significantly higher that of the organic conjugates.

Conclusions: While QDs are noted for their superior spectral characteristics, they have been shown here to be unsuitable for conventional flow cytometric detection of Cryptosporidium. Therefore, we conclude that in their current form, QD's are severely limited for fluorescent detection of pathogens in environmental applications. (c) 2007 International Society for Analytical Cytology.

Original languageEnglish
Pages (from-to)265-271
Number of pages7
JournalCytometry Part A
Volume71A
Issue number4
DOIs
Publication statusPublished - Apr 2007

Keywords

  • Quantum Dots
  • Cryptosporidium
  • monoclonal antibodies
  • antibody binding
  • flow cytometry
  • non-specific binding
  • organic fluorophores
  • fluorescence intensity
  • autofluorescence
  • environmental samples
  • ENVIRONMENTAL WATER SAMPLES
  • IMMUNOMAGNETIC SEPARATION
  • PARVUM OOCYSTS
  • GIARDIA
  • IMMUNOFLUORESCENCE
  • FLUOROCHROMES
  • SIZE

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