Assays are key tools to diagnose diseases

Dec. 22, 2021

Assays are at the core of any clinical laboratory operation. Indeed, more than 7 billion lab tests are performed in the United States each year, according to the American Clinical Laboratory Association.1

In 2019, Medicare alone spent $7.68 billion on lab tests, ranging from HbA1c assays to genetic tests associated with various types of cancer. When measured by total spending, the most common tests among Medicare beneficiaries are blood tests, including those measuring a comprehensive group of blood chemicals; lipids, thyroid stimulating hormone, and a complete blood cell count.2

But a conversation about lab testing is not complete without mentioning SARS-CoV-2. Since the beginning of the COVID-19 pandemic in 2020, U.S. clinical labs have performed more than 673.5 million tests to detect the virus, the Centers for Disease Control and Prevention (CDC) reported.3

Medical Laboratory Observer features a small sampling of assays in this issue.

SARS-CoV-2 or flu assays 

Microfluidic immunofluorescence assay

The LumiraDx SARS-CoV-2 Ag Test is a rapid microfluidic immunofluorescence assay for use with the LumiraDx Platform intended for the qualitative detection of the nucleocapsid protein antigen to SARS-CoV-2 directly from anterior nasal swab and nasopharyngeal swab samples collected from individuals suspected of COVID-19 by their healthcare provider within the first twelve days of symptom onset or from individuals without symptoms or other epidemiological reasons to suspect COVID-19. LumiraDx

Rapid flu test

The Immunocard STAT! Flu A&B is a rapid qualitative test for the differentiated detection of influenza A and B directly from nasal swab, nasopharyngeal swab, and nasopharyngeal aspirate/washes specimens from patients with signs and symptoms of respiratory infection. Results in 10-15 minutes for positives and 15 minutes for negative samples. It is a CLIA-waived test. Meridian Bioscience

Lateral flow antigen test

The Sofia 2 SARS Antigen FIA is a lateral-flow test, read by Quidel’s Sofia 2 Fluorescent Immunoassay Analyzer, for rapid detection of SARS-CoV-2 from anterior nares specimens. It delivers accurate, objective, automated results in 15 minutes. Workflows include a walk-away mode for individual tests and read-now mode for batch processing. Quidel

SARS-CoV-2 variant detection

The NEXTFLEX Variant-Seq SARS-CoV-2 Kit v2 detects all mutations associated with SARS-CoV-2 variants in a PCR-positive sample. With the incorporation of normalization beads, this kit reduces turn-around time by three hours. 1,536 UDIs incorporated in the kit enable the sequencing of 6,000 SARS-CoV-2 libraries in one flow cell. PerkinElmer

PCR assays

Seegene’s high multiplex real-time PCR assays include research-use-only tests designed to detect SARS-CoV-2 variants (including Delta and Omicron). The tests are compatible with Seegene STARlet, which is a liquid-handling workstation designed to manage primary sample tubes to nucleic acid (NA) extraction and PCR setup. Seegene

IgG antibody test

Ortho Clinical Diagnostics’ COVID-19 IgG Quantitative Test is an antibody test calibrated to the International Standard for anti-SARS-CoV-2 IgG antibodies from the World Health Organization (WHO). It is a standard tool to measure antibody response and intended for use as an aid in identifying individuals with an adaptive immune response to SARS-CoV-2. Ortho Clinical Diagnostics

Respiratory panel

The QIAstat-Dx Respiratory SARS-CoV-2 Panel, which runs on the QIAstat-Dx
Analyzer, uses real-time PCR to detect 21 respiratory pathogens in about an hour. The QIAstat-Dx Analyzer and cartridges are designed as a closed system that contains all necessary reagents, ensuring a fast and easy workflow. Qiagen

SARS-CoV-2 and flu combo test

The Aptima SARS-CoV-2/Flu Assay is available for simultaneous detection and differentiation of three respiratory viruses - SARS-CoV-2, influenza A and influenza B. Hologic’s multiplex test runs on Hologic’s fully automated Panther system, which provides initial results in approximately three hours and can process more than 1,000 tests in 24 hours. Hologic

Point-of-care test

The CLIA-waived Acucy Influenza A&B Test on the Acucy System is a rapid (result in 15 minutes) chromatographic immunoassay that provides clinicians with flexibility in the workflow, with read-now or walk-away mode, easy transfer of results to the electronic health record (EHR), and standardized results for improved patient care. Sekisui Diagnostics

Miscellaneous assays

HPV assay

The BD Onclarity HPV Assay with extended genotyping can individually identify and track persistence for high-risk HPV genotypes beyond 16 and 18, including HPV 31, which poses a similar risk for cervical pre-cancer and cancer, as compared to HPV 18. BD

Alzheimer’s disease assay

The Randox apolipoprotein E4 (ApoE4) assay saves laboratories time and money by eliminating the requirement for genetic ApoE4 testing. The direct determination of ApoE4 status from a plasma sample can be applied to determine Alzheimer’s disease in basic clinical research, as well as in personalized medicine. The test runs on the Evidence Investigator analyzer. Randox

Body fluid assays

Beckman Coulter’s body fluids module, with linearity down to zero, provides a fully automated method for the analysis of RBC count and nucleated cell count in cerebrospinal, synovial and serous fluids. Digital flow morphology technology isolates particles in body fluids to provide immediate, accurate, and reproducible results that can be verified on screen on the DxU Microscopy Series. Beckman Coulter

Bacterial immunoassay

Hardy Diagnostics is the United States’ authorized distributor of the NG-Test CARBA 5. CARBA 5 is a rapid (15-minute) multiplex immunoassay for the detection and differentiation of the five most common carbapenemases from bacterial cultures of Enterobacterales and Pseudomonas aeruginosa. Thet test is manufactured by NG Biotech. Hardy Diagnostics.


1.Value of lab testing. American Clinical Laboratory Association. Accessed December 9, 2021.
2. U.S. Department of health and Human Services Office of the Inspector General. Data Brief. Despite Savings on many lab tests in 2019, total Medicare spending increased slights because of increased utilization for certain high-priced tests. Accessed December 9, 2021.
3. Centers for Disease Control and Prevention. COVID data tracker. United States COVID-19 cases, deaths, and laboratory testing (NAATs) by state, territory, and jurisdiction Accessed December 9, 2021.