@article{
author = "Mladenović Stokanić, Maja and Simović, Ana and Jovanović, Vesna B. and Radomirović, Mirjana and Udovićki, Božidar and Krstić Ristivojević, Maja and Đukić, Teodora and Vasović, Tamara and Aćimović, Jelena and Sabljić, Ljiljana and Lukić, Ivana and Kovačević, Ana and Cujić, Danica and Gnjatović, Marija and Smiljanić, Katarina and Stojadinović, Marija and Radosavljević, Jelena and Stanić-Vučinić, Dragana and Stojanović, Marijana and Rajković, Andreja and Ćirković Veličković, Tanja",
year = "2023",
abstract = "In this study, a cost-effective sandwich ELISA test, based on polyclonal antibodies, for routine quantification SARS-CoV-2 nucleocapsid (N) protein was developed. The recombinant N protein was produced and used for the production of mice and rabbit antisera. Polyclonal N protein-specific antibodies served as capture and detection antibodies. The prototype ELISA has LOD 0.93 ng/mL and LOQ 5.3 ng/mL, with a linear range of 1.52–48.83 ng/mL. N protein heat pretreatment (56 °C, 1 h) decreased, while pretreatment with 1% Triton X-100 increased analytical ELISA sensitivity. The diagnostic specificity of ELISA was 100% (95% CI, 91.19–100.00%) and sensitivity was 52.94% (95% CI, 35.13–70.22%) compared to rtRT-PCR (Ct < 40). Profoundly higher sensitivity was obtained using patient samples mostly containing Wuhan-similar variants (Wuhan, alpha, and delta), 62.50% (95% CI, 40.59 to 81.20%), in comparison to samples mostly containing Wuhan-distant variants (Omicron) 30.00% (6.67–65.25%). The developed product has relatively high diagnostic sensitivity in relation to its analytical sensitivity due to the usage of polyclonal antibodies from two species, providing a wide repertoire of antibodies against multiple N protein epitopes. Moreover, the fast, simple, and inexpensive production of polyclonal antibodies, as the most expensive assay components, would result in affordable antigen tests.",
publisher = "MDPI",
journal = "International Journal of Molecular Sciences",
title = "Sandwich ELISA for the Quantification of Nucleocapsid Protein of SARS-CoV-2 Based on Polyclonal Antibodies from Two Different Species",
volume = "25",
number = "1",
pages = "333",
doi = "10.3390/ijms25010333"
}