Coronavirus Devices: How Do They Test for COVID-19?

Table of Contents

1. Introduction
2. Testing Methodologies
3. Company Solutions
4. References

Introduction

The COVID-19 pandemic has necessitated the development of rapid and reliable testing methods to manage and control the spread of the virus. Understanding the mechanisms behind these testing devices is essential for healthcare professionals and the general public. This article lays out the scientific principles of COVID-19 testing devices, their methodologies, and solutions proposed by leading companies in the field.

Testing Methodologies

Polymerase Chain Reaction (PCR) Tests

PCR tests are considered the gold standard in COVID-19 testing. They work by amplifying the viral RNA to detectable levels. A typical test requires nasopharyngeal swabs and can detect viral loads as low as 10 viral particles per microliter.

Antigen Tests

These are rapid tests that detect viral proteins. Antigen tests provide results in 15–30 minutes and have a sensitivity of approximately 85% and specificity of 98%. They are useful for screening purposes in high-exposure settings.

Antibody Tests

Antibody tests determine past infection by detecting antibodies in the blood. These tests take longer (several hours) and are crucial for epidemiological studies. The sensitivity and specificity vary based on the time elapsed since infection.

Company Solutions

Roche Diagnostics

Roche offers the cobas® SARS-CoV-2 Test, a highly sensitive PCR test. It can process up to 96 tests in about 3.5 hours with a detection limit of 100 viral copies per mL.

Abbott Laboratories

Abbott developed the BinaxNOW COVID-19 Antigen Card, a rapid antigen test. This test is CLIA-waived and provides results in 15 minutes with a sensitivity of 84.6% and specificity of 98.5%.

Thermo Fisher Scientific

The TaqPath COVID-19 Combo Kit by Thermo Fisher combines PCR technology with a detection threshold as low as 10 viral copies per reaction. It can process 94 samples simultaneously in under 3 hours.

References

1. World Health Organization. Laboratory testing for coronavirus disease 2019 (COVID-19) in suspected human cases. Interim guidance. (2020).
2. Loeffelholz, M. J., & Tang, Y. W. Laboratory diagnosis of emerging human coronavirus infections – the state of the art. Emerging Microbes & Infections, 9(1), 747-756. DOI:10.1080/22221751.2020.1745095.
3. Roche Diagnostics. Overview of the cobas® SARS-CoV-2 Test. Accessed October 2023.
4. Abbott Laboratories. BinaxNOW™ COVID-19 Ag Card. Accessed October 2023.
5. Thermo Fisher Scientific. TaqPath™ COVID-19 Combo Kit. Accessed October 2023.