title: Surface plasmon resonance imaging for ABH antigen detection on red blood cells and in saliva: secretor status-related ABO subgroup identification.
abstract: Low antigenic expression of ABO subgroup system on red blood cell (RBC) is cause of discrepancy between forward and reverse blood typing in the standard agglutination technique. Neutralization agglutination is employed for verification of the detection of ABH substances in saliva. However, the neutralization technique is complicated, time-consuming and requires expertise. To overcome these drawbacks, surface plasmon resonance (SPR) imaging was developed for ABH antigen detection on RBCs and in saliva. An antibody array was designed to classify the ABO subgroups by anti-A, anti-B, and anti-H antibodies; the array was immobilized on a carboxymethyl-dextran sensor-surface. RBCs and saliva specimens from sixty-four donors were analysed by passing them over the antibody array, where the secretor status and blood group could be simultaneously identified. Consequently, the immobilized antibodies could specifically and quantitatively detect the ABH antigen on RBCs. Using the direct assay, the SPR signal of saliva detection was weaker than that of RBC detection. However, a sandwich assay with a mixture of anti-A, anti-B, and anti-H antibodies could efficiently enhance the signal. The sensor chip provided high specificity (cut-off at 100 to 175 micro refractive index units) and high precision at 0.06%-4.9% CV. The blood group results of the sixty-four donor specimens obtained by SPR agreed with the standard agglutination test with 100% accuracy. SPR could indicate different ABH antigen densities on the RBCs and nearly the same amounts of ABH substances in the saliva of strong and weak subgroups. Finally, we also demonstrated reduced assay time and fewer complications with the SPR imaging platform compared to the neutralization technique.
authors.affiliation: Center of Intelligent Materials and Systems, Nanotec Center of Excellence at Mahidol University, Thailand. toemsak.sri@mahidol.ac.th.
authors.forename: Patjaree
authors.initials: P
authors.lastname: Peungthum
authors.forename: Krisda
authors.initials: K
authors.lastname: Sudprasert
authors.forename: Ratthasart
authors.initials: R
authors.lastname: Amarit
authors.forename: Armote
authors.initials: A
authors.lastname: Somboonkaew
authors.forename: Boonsong
authors.initials: B
authors.lastname: Sutapun
authors.forename: Apirom
authors.initials: A
authors.lastname: Vongsakulyanon
authors.forename: Wuttigrai
authors.initials: W
authors.lastname: Seedacoon
authors.forename: Pimpun
authors.initials: P
authors.lastname: Kitpoka
authors.forename: Mongkol
authors.initials: M
authors.lastname: Kunakorn
authors.forename: Toemsak
authors.initials: T
authors.lastname: Srikhirin
mesh_terms: D000017:ABO Blood-Group System / Q000032:analysis*; D055910:Antibodies, Immobilized; D001788:Blood Grouping and Crossmatching; D004912:Erythrocytes / Q000737:chemistry*; D006801:Humans; D012463:Saliva / Q000737:chemistry*; D020349:Surface Plasmon Resonance
chemical_list: D000017:ABO Blood-Group System; D055910:Antibodies, Immobilized