SiM20 Posters

Sensors in Medicine 2020 38 Introduction Detection of viruses and virus-neutralizing antibodies using synthetic erythrocytes and a low-cost laminated device Ana Sánchez-Cano 1,2 , Ilhoon Jang 3 , Zachary Call 3 , Cristina Andrés 4 , Tomás Pumarola 4 , Andrés Antón 4 , Charles S. Henry 3 , Eva Baldrich 1* . The hemagglutination (HA) and haemagglutination inhibition assays (HA) are classical methods used worldwide for pathogen identification, neutralizing antibody characterization and titration, and vaccine production monitoring. Although efficient, they entail the use of fresh erythrocytes and subjective interpretation of their sedimentation pattern, which results in high variability of the results produced. 1 Diagnostic Nanotools Group, Cibbim-Nanomed., Vall d’Hebron Institut de Recerca (VHIR), ES 2 Universitat Autònoma de Barcelona (UAB), Bellaterra, ES 3 Colorado State University, Fort Collins, CO, USA 4 Respiratory Viruses Unit, Microbiology Department, Vall d’Hebron Hospital Universitari, ES Results (1). Synthrocytes Mammalian / Avian Hemagglutination Fig. 1. HA and HAI assays. (Center) Erythrocytes sediment over time. (Left) In the presence of certain pathogens, such as influenza virus, erythrocytes agglutinate and remain in solution. (Right) In HAI, hemagglutination is inhibited by anti-influenza antibodies. 2 4 8 16 32 No Virus Influenza A H1N1 virus (diluted 1 in) Fig 2. Erythrocytes (bottom) can be replaced in HA assays by a synthetic reagent, called synthrocyte (top), that displays similar agglutination behaviour in the presence of influenza A H1N1 and B viruses. 5 µm Fig 3. Synthrocyte scheme. Synthrocytes are made of silica-based beads, modified chemically with a glycoprotein bioreceptor. Bead: sedimentation capacity Bioreceptor: virus binding ability α-H1N1 Neg Antiserum Control No Virus H1N1 (4 HAU) + anti-serum (diluted 1 in) 2 0 4 0 8 0 16 0 3 2 0 64 0 128 0 α-H1N1 Neg Antiserum Fig 4. Agglutination inhibition HAI-like assay performed with synthrocytes (top) or human erythrocytes (bottom), which were incubated for 5 and 60 min, respectively, with influenza AH1N1 virus and either anti-H1N1 or control antiserum (WHO reference reagents provided by the CDC, Atlanta). Synthrocytes allow performing HAI-like assays using the reference reagents and procedure recommended by the WHO. Here, synthetic erythrocytes ( synthrocytes ) and a low-cost device for HAI automation were developed.