Applications of Cytometry Flow to COVID-19

Back in December 2019, a group of patients in Wuhan, China, developed pneumonia of unknown etiology. Since then, the full genome of the acute acute coronavirus 2 (SARS-CoV-2) respiratory syndrome has been traced and has spread worldwide leading to a global pandemic.

covid testImage credit: CrispyPork /

In just one year, there have been more than 71 million confirmed cases of the virus, claiming more than 1.6 million lives. All parts of the world have been affected, with 220 countries, regions or regions reporting issues.

Although most people with SARS-CoV-2 have only mild to moderate symptoms of the respiratory illness and tend to recover without the need for hospitalization, people in groups “ the risk ”, such as those with cancer, cardiovascular disease, chronic respiratory disease, and the elderly are more likely to become seriously ill and die.

To address the spread of the disease, the World Health Organization (WHO) has focused on conducting more extensive testing, among other strategies, such as prevention strategies and contact detection.

In terms of testing, there are currently two types of testing, real-time PCR (RT-PCR) and blood antibody-based tests. New research has helped develop another test method that could be extremely useful in increasing the testing capacity of COVID-19, helping countries around the world to tackle the pandemic SARS-CoV-2.

Scientists in Mumbai recently published a paper in the journal Virology in the future. This action creates a measurable fluorescence signal, allowing scientists to detect the presence of the virus in a sample.

COVID-19 tests currently in use

Currently, two types of testing are widely used to detect SARS-CoV-2. The first is molecular tests, such as reverse-polymerase chain reaction (RT-PCR tests) that detect the genetic material of the virus, and antigen tests that look for known proteins associated with the virus. Both of these tests can be used to diagnose congenital SARS-CoV-2 infection.

The second class of diagnostic tests is antibody tests. These tests detect the presence of antibodies in the generated blood in response to infection with a virus. However, antibodies take time to build up in the body and can lie down after the infection has cleared. Therefore, these tests can only be used to determine if someone has contracted the virus, they do not make a diagnosis.

Experts have pointed out the importance of an accurate and accessible COVID-19 test in mediating the spread of the virus. This is especially important while we are waiting for the vaccine to be rolled out, and so that we can identify a successful treatment strategy to protect those at risk.

Although PCR testing has long been considered the gold standard, the process is lengthy and system mobility is low. Moreover, antibody-based detection accuracy is not high enough to be immune to false or nonspecific results. Due to the small number of routine tests, an accurate, high-throughput and fast verification method is required.

Using Flow Cytometry to Detect COVID-19

New research has suggested another cytometry-based test method for the SARS-CoV-2 virus. Flow cytometry is a technique used across different fields of science to analyze single cells or fragments. The technology converts each grain to lasers and measures the resulting visible light scattering as well as one or more fluorescence parameters.

Data collected on light scattering can reveal cell size, as well as granularity and intra-cell complexity. The samples are stained with fluorescent dyes and fluorescent antibodies that allow scientists to detect viruses or specific antibodies to viruses.

The team in Mumbai has developed flow cytometry technology to establish a new method for SARS-CoV-2 virus testing. They believe their approach will improve the COVID-19 case test scale. The SARS-CoV-2 is constructed with a 29-30 kb layer of advanced single-stranded RNA. Its size is between 70 and 90 nm.

Previous studies have shown the detection of the dengue virion (40–60 nm) using a combination of antibodies with fluorescent bile and magnetic nanoparticles (MNP). In their new paper, the team in Mumbai describes how they have modified this approach, labeling the surface of the viral granules with primary antibodies specific for antigen and follow up with a fluorescentin-linked secondary antibody to identify the presence of SARS-CoV-2. virus.

The new method based on flow cytometry is likely to be critical for future COVID-19 testing. The new study demonstrates how the spectra of SARS-CoV-2 can be effectively tagged by fluorescent bile-specific antibodies, detected using advanced flow virometry in a high-throughput method . The newly established test could process approximately 2,000 tests per day using a single set of equipment, offering a reliable, fast, and accurate test method.


Coronavirus. World Health Organization. Available at:

Basics of Coronavirus Disease Test 2019. U.S. Food and Drug Administration. Available at:…/coronavirus-disease-2019-testing-basics

Coronavirus disease (COVID-19) is a contagious disease. World Health Organization. Available at:

McKinnon, K., 2018. Cytometry Flow: A Review. Standard Protocols in Immunology, 120 (1).

Soni, N., Pai, P., Krishna Kumar, G., Prasad, V., Dasgupta, S. and Bhadra, B., 2020. A flow virometry process has been proposed for the detection and quantification of SARS-CoV-2. screening scale of COVID-19 cases. Virology in the future, 15 (8), pp.525-532.

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