Rapid Antigen Test Kit for COVID-19 developed by IIT Delhi

Context:

Minister of State for Education Shri Sanjay Dhotre launched a Rapid Antigen Test kit for COVID-19 developed by IIT Delhi today.

About Rapid Antigen Test Kit:

1. This kit is used for in vitro qualitative detection of SARS-CoV-2 antigen.
2. The SARS-CoV-2 Ag Rapid Test is a colloidal gold enhanced double antibody sandwich immunoassay for the qualitative determination of SARS-CoV-2 antigen in human nasal swabs, throat swabs and deep sputum samples. It is suitable for general population screening and diagnosis of COVID-19.
3. The invention is directed towards an in vitro diagnostic kit for qualitative detection of SARS-CoV-2 coronavirus antigens in nasopharyngeal swab, using the rapid immune chromatographic method.
4. The identification is based on the monoclonal antibodies specific for the Coronavirus antigen.
5. The results obtained are qualitative based and can be inferred visually with naked eye.
6. A SARS-CoV-2 positive specimen produces a distinct color band in the test region, formed by the specific antibody antigen colored conjugate complex”(Au-SARS-CoV-2-Ab)-(SARS-CoV-2-Ag)-(SARS-CoV-2-Ab)”. Absence of this colored band in the test region suggests a negative result.
7. A colored band always appears in the control region serving as procedural control regardless of the specimen contains SARS-CoV-2 or not.
8. Test is found to be suitable for early Ct values (Ct values between 14 to 32) with a Sensitivity- 90%, Specificity- 100% and Accuracy- 98.99%, and certified by the ICMR. These are the one of the best available values for any such test kits.
9. The technology and its manufacturing are 100% indigenous.

Antigen

Antigen, substance that is capable of stimulating an immune response, specifically activating lymphocytes, which are the body’s infection-fighting white blood cells. In general, two main divisions of antigens are recognized: foreign antigens (or heteroantigens) and autoantigens (or self-antigens).

Foreign antigens originate from outside the body. Examples include parts of or substances produced by viruses or microorganisms (such as bacteria and protozoa), as well as substances in snake venom, certain proteins in foods, and components of serum and red blood cells from other individuals.

Auto-antigens, on the other hand, originate within the body. Normally, the body is able to distinguish self from nonself, but in persons with autoimmune disorders, normal bodily substances provoke an immune response, leading to the generation of autoantibodies. An antigen that induces an immune response—i.e., stimulates the lymphocytes to produce antibody or to attack the antigen directly—is called an immunogen.

Antibody:

An antibody is a protein component of the immune system that circulates in the blood, recognizes foreign substances like bacteria and viruses, and neutralizes them. After exposure to a foreign substance, called an antigen, antibodies continue to circulate in the blood, providing protection against future exposures to that antigen.

RT-PCR

Reverse transcription polymerase chain reaction (RT-PCR) is a laboratory technique combining reverse transcription of RNA into DNA (in this context called complementary DNA or cDNA) and amplification of specific DNA targets using polymerase chain reaction (PCR). It is primarily used to measure the amount of a specific RNA. This is achieved by monitoring the amplification reaction using fluorescence, a technique called real-time PCR or quantitative PCR (qPCR). Combined RT-PCR and qPCR are routinely used for analysis of gene expression and quantification of viral RNA in research and clinical settings.

Source: PIB