LEGENDplex™ SARS-CoV-2 Variants Neut. Ab Panel (5-plex) w/ FP from BIOLEGEND

SARS-CoV-2 infection, known as COVID-19, was declared a pandemic in 2020. Among a range of symptoms pulmonary failure can be fatal, which poses a significant threat to global public health.  SARS-CoV-2 is a single stranded RNA virus and structurally composed of 4 main proteins (e.g. spike glycoprotein, envelope glycoprotein, membrane glycoprotein and nucleocapsid protein) and several accessory proteins. SARS-CoV-2 continuously evolves as changes in the genetic code occur during replication of the genome. SARS-CoV-2 variants have been emerging and circulating around the world since the beginning of the COVID-19 pandemic, e.g. Alpha (B.1.1.7, first identified in the United Kingdom), Beta (B.1.351, first identified in South Africa), Gamma (P.1, first identified in Brazil), Delta (B.1.617.2, first identified in India), etc. Among the variants, Delta has been defined as Variant of Concern (VOC) for which there is evidence of increased transmissibility and disease severity, significantly decreased neutralization by antibodies generated during previous infection or vaccination, reduced effectiveness of treatment or vaccines.

LEGENDplex™ SARS-CoV-2 Variants Neut. Ab Panel (5-plex) is a multiplex beads-based competitive assay. Capture beads are 5 SARS-CoV-2 Spike protein Variants (Variant Alpha, Variant Beta, Variant Gamma, Wild type S1 protein and Variant Delta) conjugated onto fluorochrome-coded beads. Biotinylated ACE2 protein serving as the Detection will be added to all wells after adding the beads. Standard (anti-human S1 RBD recombinant antibody) or samples and Detection will compete to bind to the capture beads, producing a competitive assay. Streptavidin-phycoerythrin (SA-PE) is subsequently added, which will bind to the biotinylated detection, providing fluorescent signal intensities in proportion to the amount of bound analytes. The concentration of a neutralization antibody is determined using a standard curve generated in the same assay. The competition between the detection and the standard neutralization antibody will form an inverted standard curve. Due to the nature of the assay, the standard curve will have the highest signal at the lowest standard neutralization antibody concentration and the signal will decrease as the standard neutralization antibody concentration increases.