SARS‑CoV‑2 Antibodies (IgG Nucleocapsid, IgM Spike), Qualitative

Casandra

Casandra Test Code QD23076Version 1 (DRAFT)

Performing Lab

Lab Quest DiagnosticsLab Test ID 31672

SARS‑CoV‑2 Antibodies (IgG Nucleocapsid, IgM Spike), Qualitative

Also known as: Novel Coronavirus, Wuhan, COVID19, nCOV, Coronavirus

Clinical Use

Order Test

Use

Intended for qualitative detection of both IgG antibodies targeting SARS‑CoV‑2 nucleocapsid and IgM antibodies targeting SARS‑CoV‑2 spike in human serum or plasma, as an aid in identifying recent or prior infection and adaptive immune response to SARS‑CoV‑2. Not for diagnosing or excluding acute infection; the clinical significance of antibodies (especially post‑vaccination) and their persistence are not well characterized and may not indicate protective immunity. ([questdiagnostics.com](https://www.questdiagnostics.com/healthcare-professionals/clinical-education-center/faq/faq219?utm_source=openai))

Special Instructions

This panel includes separate qualitative results for IgG (nucleocapsid) and IgM (spike) antibodies. Testing is performed using EUA-authorized immunoassays under CLIA/CAP verification. Useful for distinguishing infection-mediated antibody response; IgG to nucleocapsid is not expected to result from spike‑only vaccination. ([questdiagnostics.com](https://www.questdiagnostics.com/healthcare-professionals/about-our-tests/infectious-diseases/covid-19/antibody?utm_source=openai))

Limitations

Not intended for diagnosis of acute SARS‑CoV‑2 infection. Timing of antibody response varies; false negatives can occur early post-infection. The duration of detectability of IgG and IgM antibodies post-infection is not well defined, and presence of antibodies does not guarantee immunity. Cross-reactivity or background reactivity may occur; results must be interpreted with clinical context and other testing. Performance characteristics post-vaccination are not established. ([questdiagnostics.com](https://www.questdiagnostics.com/healthcare-professionals/clinical-education-center/faq/faq219?utm_source=openai))

Test Details

FDA Approved