title: Development of a quantum-dot-labelled magnetic immunoassay method for circulating colorectal cancer cell detection.
abstract: OBJECTIVE
  To detect of colorectal cancer (CRC) circulating tumour cells (CTCs) surface antigens, we present an assay incorporating cadmium selenide quantum dots (QDs) in these paper.
  
  
  METHODS
  The principle of the assay is the immunomagnetic separation of CTCs from body fluids in conjunction with QDs, using specific antibody biomarkers: epithelial cell adhesion molecule antibody, and monoclonal cytokeratin 19 antibody. The detection signal was acquired from the fluorescence signal of QDs. For the evaluation of the performance, the method under study was used to isolate the human colon adenocarcinoma cell line (DLD-1) and CTCs from CRC patients' peripheral blood.
  
  
  RESULTS
  The minimum detection limit of the assay was defined to 10 DLD-1 CRC cells/mL as fluorescence was measured with a spectrofluorometer. Fluorescence-activated cell sorting analysis and Real Time RT-PCR, they both have also been used to evaluate the performance of the described method. In conclusion, we developed a simple, sensitive, efficient and of lower cost (than the existing ones) method for the detection of CRC CTCs in human samples. We have accomplished these results by using magnetic bead isolation and subsequent QD fluorescence detection.
  
  
  CONCLUSIONS
  The method described here can be easily adjusted for any other protein target of either the CTC or the host.
authors.affiliation: Department of Basic Medical Sciences, Laboratory of Biology, School of Medicine, University of Athens, 11527 Athens, Greece. mgazouli@med.uoa.gr
authors.forename: Maria
authors.initials: M
authors.lastname: Gazouli
authors.forename: Anna
authors.initials: A
authors.lastname: Lyberopoulou
authors.forename: Pericles
authors.initials: P
authors.lastname: Pericleous
authors.forename: Spyros
authors.initials: S
authors.lastname: Rizos
authors.forename: Gerassimos
authors.initials: G
authors.lastname: Aravantinos
authors.forename: Nikolaos
authors.initials: N
authors.lastname: Nikiteas
authors.forename: Nicholas P
authors.initials: NP
authors.lastname: Anagnou
authors.forename: Efstathios P
authors.initials: EP
authors.lastname: Efstathopoulos
mesh_terms: D000230:Adenocarcinoma / Q000175:diagnosis* / Q000276:immunology / Q000473:pathology; D000906:Antibodies / Q000097:blood; D000951:Antigens, Neoplasm / Q000276:immunology; D016022:Case-Control Studies; D015815:Cell Adhesion Molecules / Q000276:immunology; D015179:Colorectal Neoplasms / Q000175:diagnosis* / Q000276:immunology / Q000473:pathology; D000071858:Epithelial Cell Adhesion Molecule; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D018189:Immunomagnetic Separation / Q000379:methods*; D053539:Keratin-19 / Q000276:immunology; D045663:Quantum Dots; D012680:Sensitivity and Specificity; D013050:Spectrometry, Fluorescence
chemical_list: D000906:Antibodies; D000951:Antigens, Neoplasm; D015815:Cell Adhesion Molecules; D000071858:Epithelial Cell Adhesion Molecule; D053539:Keratin-19