title: Blood group antigen studies using CdTe quantum dots and flow cytometry.
abstract: New methods of analysis involving semiconductor nanocrystals (quantum dots [QDs]) as fluorescent probes have been highlighted in life science. QDs present some advantages when compared to organic dyes, such as size-tunable emission spectra, broad absorption bands, and principally exceptional resistance to photobleaching. Methods applying QDs can be simple, not laborious, and can present high sensibility, allowing biomolecule identification and quantification with high specificity. In this context, the aim of this work was to apply dual-color CdTe QDs to quantify red blood cell (RBC) antigen expression on cell surface by flow cytometric analysis. QDs were conjugated to anti-A or anti-B monoclonal antibodies, as well as to the anti-H (Ulex europaeus I) lectin, to investigate RBCs of A1, B, A1B, O, A2, and Aweak donors. Bioconjugates were capable of distinguishing the different expressions of RBC antigens, both by labeling efficiency and by flow cytometry histogram profile. Furthermore, results showed that RBCs from Aweak donors present fewer amounts of A antigens and higher amounts of H, when compared to A1 RBCs. In the A group, the amount of A antigens decreased as A1 > A3 > AX = Ael, while H antigens were AX = Ael > A1. Bioconjugates presented stability and remained active for at least 6 months. In conclusion, this methodology with high sensibility and specificity can be applied to study a variety of RBC antigens, and, as a quantitative tool, can help in achieving a better comprehension of the antigen expression patterns on RBC membranes.
authors.affiliation: Departamento de Biofísica e Radiobiologia, Universidade Federal de Pernambuco, Recife, Pernambuco, Brazil.
authors.forename: Paulo E
authors.initials: PE
authors.lastname: Cabral Filho
authors.affiliation: Departamento de Biofísica e Radiobiologia, Universidade Federal de Pernambuco, Recife, Pernambuco, Brazil.
authors.forename: Maria I A
authors.initials: MI
authors.lastname: Pereira
authors.affiliation: Centro de Hematologia e Hemoterapia, Universidade Estadual de Campinas, Instituto Nacional de Ciência e Tecnologia do Sangue, Campinas, São Paulo, Brazil.
authors.forename: Heloise P
authors.initials: HP
authors.lastname: Fernandes
authors.affiliation: Departamento de Eletrônica Quântica, Instituto de Física Gleb Wataghin, Universidade Estadual de Campinas, Campinas, São Paulo, Brazil.
authors.forename: Andre A
authors.initials: AA
authors.lastname: de Thomaz
authors.affiliation: Departamento de Eletrônica Quântica, Instituto de Física Gleb Wataghin, Universidade Estadual de Campinas, Campinas, São Paulo, Brazil.
authors.forename: Carlos L
authors.initials: CL
authors.lastname: Cesar
authors.affiliation: Departamento de Ciências Farmacêuticas, Universidade Federal de Pernambuco, Recife, PE, Brazil.
authors.forename: Beate S
authors.initials: BS
authors.lastname: Santos
authors.affiliation: Centro de Hematologia e Hemoterapia, Universidade Estadual de Campinas, Instituto Nacional de Ciência e Tecnologia do Sangue, Campinas, São Paulo, Brazil.
authors.forename: Maria L
authors.initials: ML
authors.lastname: Barjas-Castro
authors.affiliation: Departamento de Biofísica e Radiobiologia, Universidade Federal de Pernambuco, Recife, Pernambuco, Brazil.
authors.forename: Adriana
authors.initials: A
authors.lastname: Fontes
mesh_terms: D000911:Antibodies, Monoclonal; D001789:Blood Group Antigens / Q000097:blood*; D019187:Cadmium Compounds / Q000737:chemistry*; D004912:Erythrocytes / Q000737:chemistry; D005434:Flow Cytometry / Q000379:methods*; D006801:Humans; D045663:Quantum Dots / Q000737:chemistry*; D013691:Tellurium / Q000737:chemistry*
chemical_list: D000911:Antibodies, Monoclonal; D001789:Blood Group Antigens; D019187:Cadmium Compounds; D013691:Tellurium; C028337:cadmium telluride
keywords: ABO antigens; carbohydrates; covalent binding; erythrocytes; nanoparticles