Antigen Test for COVID-19: How Is It Different from Coronavirus Testing

rapid antigen test for covid19


What is Rapid Antigen Test for COVID-19?


The Rapid Antigen Detection Test (RADT) for COVID-19 is a rapid point-of-care nasopharyngel swab test that directly detects the presence or absence of coronavirus antigen in the patient’s body, generating diagnosis results within 30 minutes. These tests are designed to detect a specific protein in the virus that elicits the body’s immune response.


RT-PCR, though highly accurate, requires complex bio safety compliant set ups and takes longer to give a result. We are thus seeing longer turnaround times as the number of cases rise. The antigen testing solves this problem to an extent as apart from being fast, it is highly specific and thus positive results are highly accurate.


How does an antigen test work?


An antigen is a molecule capable of stimulating an immune response. They may be proteins, polysaccharides, lipids or nucleic acids. Each antigen has distinct surface features that are recognized by the immune system.

SARS-CoV-2, the virus that causes COVID-19, has several known antigens, including its nucleocapsid phosphoprotein and spike glycoprotein, which are the visible protrusions on its surface.

An antigen test reveals if a person is currently infected with a pathogen such as the SARS-CoV-2 virus. Once the infection has gone, the antigen disappears. Unlike nucleic acid based tests such as PCR, which detect the presence of genetic material, antigen tests detect proteins or glycans, such as the spike proteins found on the surface of the SARS-CoV-2. They usually provide test results rapidly, are relatively cheap, and can be more amenable to point-of-care use, which could make them more suitable for testing in the community and in remote regions.


Where will the Rapid Detection Test be used?


According to the ICMR, the antigen test may be performed under strict medical supervision in the following settings:

  • In the containment zones to check the symptomatic influenza-like illnesses (ILI).
  • In the containment zones to test asymptomatic high risk contacts of the confirmed cases with other chronic systemic illnesses within 5 to 10 days of contact.
  • In healthcare settings, the antigen test may be used for people showing ILI symptoms, asymptomatic cancer patients, immunosuppressed individuals, elderly patients with other ailments and those undergoing dental procedures, non-surgical procedures like dialysis or surgeries which generate aerosol.


Can an Antigen Test diagnose the COVID-19?


The rapid detection test kit has been able to achieve 99.3% to 100% accuracy in detecting the true negativity. However, the specificity to discover the true positive is between 50.6% to 80%. Thus, testing must be done by maintaining the kit temperature between 2° and 30°C, and the kit will be used in containment zones or hotspots and hospital settings only.


antigen testing and coronavirus testing

How is the rapid antigen test different from Coronavirus Testing?


The significant difference between a Coronavirus Test and an Antigen Test is technology and time. For the diagnosis of COVID-19, RT-PCR test takes a minimum of 2-5 hours, including sample collection. On the other hand, a rapid antigen detection test (RADT) takes a maximum duration of 30 minutes for interpreting a positive or negative test.


What are the limitations of an antigen test’s results?


While the antigen test can be done in less time, it has certain limitations:

  • The negative results from an antigen test may need to be confirmed with a molecular PCR test.
  • Sample collection in the hospital setting is necessary. It cannot be used as a generalized test as claimed by many manufacturers.


Many laboratories and manufacturers, across the globe, are trying to develop testing kits, and scientists and researchers are working to develop the vaccination. However, people are advised to stay away from false claims and must follow the official channels and mediums to receive information.

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Hypothyroidism or Underactive Thyroid – Symptoms, Treatment, Diet

Hypothyroidism Underactive Thyroid Symptoms, Causes

What is Hypothyroidism?


Hypothyroidism, also known as Underactive Thyroid Disease is a condition in which the thyroid glands of a patient do not produce enough crucial hormones. The hormones released by thyroid gland help use the energy generated by the body and regulate its functioning. Hypothyroidism is commonly found in the geriatric population and is diagnosed at a higher rate among women than men. The procedure for the diagnosis of Hypothyroidism is through a blood test or by observing the symptoms.


What are the Signs & Symptoms of Hypothyroidism?


The signs of Hypothyroidism are sometimes difficult to identify, as they vary from person to person and depend on the severity of the condition of the patient. Majorly, it has been observed that the signs of Hypothyroidism are more evident with time. Although the disease is more relevant among the geriatric population and women, anyone can be diagnosed with Hypothyroidism. Infants, children, and teens can also be diagnosed with Hypothyroidism.
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Pneumonia Fever – Symptoms, Stages, Causes, Treatment, Cost

pneumonia fever - symptoms, causes, stages

What is Pneumonia?


Pneumonia is one of the most common health conditions we hear of. But what does pneumonia mean? In simple words, it is an infection that affects one or both lungs. Pneumonia fever can be caused by viruses, bacteria, or fungi. It is contagious and can spread from one person to another.


What are the Early Signs and Symptoms of Pneumonia?


Pneumonia can be spotted if one knows the symptoms. Some common pneumonia symptoms include:

  • Coughing and mucus
  • Fever and headaches
  • Nausea and vomiting
  • Fatigue and tiredness
  • Shortness of breath and chest pain

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Blood Sugar Levels Chart – Low, Normal & High Ranges

blood sugar low normal high range


We, at SRL Diagnostics, have a team of expert doctors that provide effective resolutions to assist patients. We believe that the best way to help people stay healthy and fit is to make them aware of the persisting diseases and provide information relating to their spread and cure. Here, in this article, we have emphasised on blood sugar-related health complications to give you a better understanding of taking care of your health.


What is Blood Sugar Level?


Our bodies contain some amount of sugar in the blood as well as body cells at all times. This sugar is the fuel for all body functions. The blood sugar level, also known as blood glucose level in the body is maintained by the hormones insulin and glucagon.

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CRP (C-reactive Protein) Test: Normal Range Level, Treatment

crp test c reactive protein testing


What is C-reactive Protein (CRP)?


C-reactive Protein is a substance produced by the liver to heal inflammation in the body. It is one of the proteins in the body referred to as ‘acute phase reactants’. The body releases these reactants to heal the inflammation, which is the body’s way of protecting tissues in case of an injury or infection. Inflammation increases the level of C-reactive protein in the bloodstream, and the CRP test means measuring that level. The test helps in finding out the risks of heart attack, stroke, and other severe conditions caused by inflammation. However, the test does not detect where the inflammation is in the body.


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Diabetes – Symptoms, Types, Causes, Treatment, Diet

diabetes types symptoms treatment diet

What is Diabetes?


Diabetes mellitus is a medical condition in which the body has more than normal blood sugar levels. Commonly referred to as diabetes, the condition is caused when the body is either unable to use the insulin effectively or the pancreas is unable to produce enough insulin. Insulin is a hormone that assists in breaking down glucose into energy. Diabetes has two common types but there are other types as well such as gestational diabetes, which occurs in women during pregnancy. SRL Diagnostics is well equipped to run tests for all types of diabetes.




Type 1 diabetes and Type 2 diabetes are the two common diabetes types. Type 1 diabetes is an uncommon but severe type of diabetes and is referred to as juvenile diabetes because it mostly affects children and teenagers. It is an autoimmune disease, in which the body’s immune system starts attacking the insulin making islet cells in the pancreas, preventing them from producing enough insulin.Read More

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