{"doi":"10.1016/j.jcv.2021.104945","title":"Development of the RealTime SARS-CoV-2 quantitative Laboratory Developed Test and correlation with viral culture as a measure of infectivity","abstract":"While diagnosis of COVID-19 relies on qualitative molecular testing for the absence or presence of SARS-CoV-2 RNA, quantitative viral load determination for SARS-CoV-2 has many potential applications in antiviral therapy and vaccine trials as well as implications for public health and quarantine guidance. To date, no quantitative SARS-CoV-2 viral load tests have been authorized for clinical use by the FDA. In this study, we modified the FDA emergency use authorized qualitative RealTime SARS-CoV-2 assay into a quantitative SARS-CoV-2 Laboratory Developed Test (LDT) using newly developed Abbott SARS-CoV-2 calibration standards. Both analytical and clinical performance of this SARS-CoV-2 quantitative LDT was evaluated using nasopharyngeal swabs (NPS). We further assessed the correlation between Ct and the ability to culture virus on Vero CCL81 cells. The SARS-CoV-2 quantitative LDT demonstrated high linearity with R2 value of 0.992, high inter- and intra-assay reproducibility across the dynamic range (SDs ± 0.08–0.14 log10 copies/mL for inter-assay reproducibility and ± 0.09 to 0.19 log10 copies/mL for intra-assay reproducibility). Lower limit of detection was determined as 1.90 log10 copies/mL. The highest Ct at which CPE was detected ranged between 28.21–28.49, corresponding to approximately 4.2 log10 copies/mL. Quantitative tests, validated against viral culture capacity, may allow more accurate identification of individuals with and without infectious viral shedding from the respiratory tract.","journal":"Journal of Clinical Virology","year":2021,"id":168763,"datarank":0.0,"base_score":0.0,"endowment":0.0,"self_citation_contribution":0.0,"citation_network_contribution":0.0,"self_endowment_contribution":0.0,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":30,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9567,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2021-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":698850,"name":"Wei Zhen","orcid":null,"position":1,"is_corresponding":false},{"id":306823,"name":"Danijela Lucic","orcid":"0000-0002-7276-489X","position":2,"is_corresponding":false},{"id":306822,"name":"Emily Degli-Angeli","orcid":"0000-0002-5644-5258","position":3,"is_corresponding":false},{"id":235418,"name":"Mark S. Anderson","orcid":"0000-0002-3093-4758","position":4,"is_corresponding":false},{"id":698851,"name":"Kenn Forberg","orcid":null,"position":5,"is_corresponding":false},{"id":698852,"name":"Ana Olivo","orcid":null,"position":6,"is_corresponding":false},{"id":561510,"name":"Farah Sheikh","orcid":"0000-0003-2610-0125","position":7,"is_corresponding":false},{"id":698853,"name":"Dan Toolsie","orcid":null,"position":8,"is_corresponding":false},{"id":108342,"name":"Alexander L. Greninger","orcid":"0000-0002-7443-0527","position":9,"is_corresponding":false},{"id":248628,"name":"Gavin Cloherty","orcid":null,"position":10,"is_corresponding":false},{"id":65748,"name":"Robert W. Coombs","orcid":"0000-0003-2709-0512","position":11,"is_corresponding":false},{"id":486332,"name":"Gregory J. Berry","orcid":"0000-0002-0767-6826","position":12,"is_corresponding":false},{"id":411181,"name":"Michael G. Berg","orcid":"0000-0003-0233-5819","position":0,"is_corresponding":true}],"reference_count":53,"raw_metadata":null,"created_at":"2026-07-18T23:46:06.853307Z","pmid":"34450558","pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}