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The SARS-CoV-2 virus is still spreading worldwide, and there is an urgent need to effectively prevent and control this pandemic. This study evaluated the potential efficacy of Egg Yolk Antibodies (IgY) as a neutralizing agent against the SARS-CoV-2. We investigated the neutralizing effect of anti-spike-S1 IgYs on the SARS-CoV-2 pseudovirus, as well as its inhibitory effect on the binding of the coronavirus spike protein mutants to human ACE2. Our results show that the anti-Spike-S1 IgYs showed significant neutralizing potency against SARS-CoV-2 pseudovirus, various spike protein mutants, and even SARS-CoV in vitro. It might be a feasible tool for the prevention and control of ongoing COVID-19.

Antibodies against human platelets cause a variety of thrombocytopenic disorders, which lead to potentially fatal haemorrhage. Therefore, their prompt detection is mandatory for successful patient treatment. Solid phase red cell adherence (SPRCA) assay allows for platelet antibody detection widely. However, preparation of fresh platelets with HLA-I and human platelet antigens (HPA)1–5,15 genotyped as target cells is inconvenient and fresh platelets have a short shelf life. In this study, the lyophilised human platelets for antibody detection in SPRCA were prepared. Firstly, platelets were resuspended in lyophilisation buffer and freeze-dried. Then the characteristics of lyophilised platelet were analysed. Rehydrated platelets were recovered with a mean rate of 80.91% ± 2.87%, and still retained spherical morphology. Indirect flow cytometry showed that glycoproteins IIb/IIIa, Ia/IIa, Ib/IX, IV, CD109, and HLA class I were present on the surface of the lyophilised platelets at a comparable level to that of fresh platelets. The consistent results obtained with WHO reference reagents containing anti-HPA-1a, anti-HPA-3a, and anti-HPA-5b, as well as clinical samples from the same donors containing anti-HLA antibodies when reacting with lyophilised versus fresh platelets confirmed good antigenicity preservation of platelets after freeze-drying. Further investigation showed that the lyophilised platelets could be stored at 2–8 °C for up to 14 months and the reconstituted suspension was stable for 48 h. Therefore, lyophilised platelets can be a convenient alternative to fresh platelets to use for anti-platelet antibody detection in SPRCA tests.

Accurate and fast identification of blood groups is a critical step in the blood transfusion procedure. In this study, we reported a rapid and reliable immunosensing assay for ABO and RhD blood group typing based on natural free-standing silk cocoon membranes. Natural silk cocoon membranes were punched into discs (SMDs) and were treated with heat and detergent to increase wettability. Monoclonal antibodies (mAbs) against silk proteins were successfully prepared through animal immunization. The SMDs were functionalized by affinity binding with specific silk mAbs and crosslinking antibodies. Blood grouping antibodies were coupled with functional SMDs to form the immunosensor for blood typing. Only three pipetting steps were required to perform the assay, without the need for any external analytical equipment. Results could be obtained and distinguished by the naked eye within 30 s, making this immunosensor suitable for point-of-care testing. A positive result was obtained when the SMD showed a visualization red spot after washing, no red spot was observed if there was no reaction. We compared our sensing results with those from the gold-standard tube test on 112 real blood samples. The accuracy was 100 %. Due to the availability of the cocoon membranes-based immunosensor and the facile fabrication process, the SMART can be scaled up easily for mass production.

Background The distribution of the Mur blood group antigen is 5–7% in the south of China, and a much higher prevalence is observed in some areas of the region. Anti-Mur can cause hemolytic disease of the newborn and severe transfusion reactions. Objectives Genetic testing is more ideal than conventional serological tests because antibodies for detection are usually not available. Methods In this study, a novel loop-mediated isothermal amplification (LAMP) assay for the detection of Mur blood group antigen was established. Results Fifteen of 275 (5·5%) samples were confirmed by LAMP as Mur antigen positive. All the Mur antigen-positive samples were GP.Mur subtype which was confirmed with sequencing. Conclusion The LAMP method has identical results with conventional serology method but more suitable for large-scale screening.

A novel microcarrier based on red blood cells was prepared and characterized. Proof of principle was demonstrated by using sheep red blood cells that were treated with glutaraldehyde to render the cells generally resistant to hemolysis. Magnetic beads of approximately 10 nm in diameter were prepared and attached to the surface of glutaraldehyde-treated sheep red blood cells by electrostatic interaction at various concentrations. The composites were characterized by scanning electron microscopy. Dilute coverage of magnetic beads allowed the red blood cells to be separated from solution in the presence of a magnetic field, eliminating the need for centrifugation. The magnetized glutaraldehyde-treated red blood cells were then functionalized with human immunoglobulin and used in flow cytometry for the determination of antihuman immunoglobulin. The results indicated that such magnetized glutaraldehyde-treated red blood cell may be used as carriers in flow cytometry. The approach may allow the preparat...

In assays for incomplete antibody detection, several washing steps are required to remove unbound globulins which may cause false negatives. Here, we present an improved approach employing hydrogel chromatography medium (HCM) in the detection of incomplete antibodies. After a rapid single-step centrifugation, incomplete antibodies, attached to red blood cells (RBCs), were separated from the reaction mixture using HCM and sedimentation. This method obviates the need for multiple centrifugation steps found in conventional Tube-Coombs tests. The HCM-Coombs tests may have a wide range of applications for incomplete antibody detection.