At present situation, the COVID-19 outbreak is disappointing every individual, every Society, every Nation and the whole World.
The necessity of Testing kits to check for the Virus among the people is need of the hour.
In this presentation, the testing kits, their types, working mechanisms, working Principle are explained in a detailed manner. Kindly go through all the slides.
2. How COVID-19 Testing kits work, what
tests are available?
COVID-19 testing is one of the key factors tackling the spread
of novel Coronavirus across the globe.
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3. For example, South Korea controlled the spread solely through
mass testing by which they identified and isolated those with
the disease.
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4. Testing is crucial to calculate the data necessary for making the
right public safety measures like accurate infection and
survival rates.
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5. During this Coronavirus pandemic, many highly-priced, non-
approved, or fake tests are offered to people for sale.
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6. So, what tests are being used by health officials, how do they
work and what developments are to come?
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8. COVID-19 can be tested
in two ways.
The first test looks for
RNA of the virus using a
technique called RT-PCR.
This test can detect even a
single virus particle in the
swap collected from the
nose or mouth of the
patient.
The second test measures the
antibody generated in blood serum
in response to the SARS-CoV-2
virus. Different types of antibodies
are generated in the body in
response to the viral components.
Some are less useful, binding to
some common parts of the virus
without helping the defense
mechanism.
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10. 1.) RT-PCR test
Real-Time Polymerase Chain Reaction is a technique used to
detect the presence of specific genetic material in the sample.
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11. To test COVID-19, the swab collected from the mouth or nose
of the patient is treated with various chemical substances to
remove substances like fats and protein and finally isolate
RNA.
The isolated RNA includes the patient’s genetic material and
that of the virus.
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12. The RNA is then reverse transcribed to DNA using specific
enzymes.
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13. DNA fragments complementary to the viral genome is then
added to this mixture of DNA.
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14. The DNA fragments will go bind to the viral genome if
present.
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15. Later the mixture is placed in a RT-PCR machine where the
target sections of viral DNA will get amplified(identical copies
generated).
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16. The marker added along with the mix will release
fluorescence, which is measured by the computer.
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17. The Computer will track the amount of fluorescence emitted,
and when the amount goes over a certain level, the presence of
the virus is confirmed.
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18. 2.) ANTIBODY TEST
This test is very simple.
A small amount of blood sample collected from the patient is
added to a test tube coated with virus “mash” or purified viral
components.
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19. If the patient is infected and carries antibodies against the
virus, they will get bound to the test tube.
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20. The test-tube is later developed to see if any antibodies are
present. If present, it confirms infection.
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22. RT-PCR test is very sensitive and specific. However, the test
cannot tell if one person was infected once he recovered as no
viral particles are present in the body.
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23. The test needs a laboratory and takes time.
It would take days to collect sample, transport, process, and to
generate results.
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24. Even the fastest cutting edge diagnostic technology, the rapid
portable RT-PCR machines can take around 2 hours!!
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25. Antibodies generally take a few weeks to develop and lasts
longer than the virus in the bloodstream.
This test is very useful in providing a historical picture of
infections.
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26. The test can identify if a person
was infected earlier, even
after recovering from
the disease.
The test is used to
diagnose the disease as well as
to check if vaccines work.
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27. However, the World Health Organisation recommends the RT-
PCR test as the current antibody tests for the nCoV and
haven’t been fully tested to make sure they are reliable.
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28. Recently the UK Government announced that they would
make 3.5 million home tests available in the country.
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29. Saliva-based antibody testing might be possible, but very less
data is available for saliva than the blood serum.
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31. There are challenges in making and using antibody tests. The
antibody test takes time to refine and needs viral components
to be produced, purified, and standardized, unlike the RT-PCR
test.
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32. Very carefully, collected sets of patient samples are needed to
check these tests are useful. The test needs to be checked with
samples from different patients, because every individual
produces a unique set of antibodies.
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33. Also, how long after the infection the sample test shows
positive and how long it works after the recovery needs to be
studied before these COVID-19 testing kits can be widely
made available.
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34. In contrast, RT-PCR detection can be assessed by taking a
known amount of virus and checking the result.
The virus has been grown in labs, and we have an accurate RT-
PCR test for some time.
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35. The overburdened labs and labor requirements for running the
test make it relatively slow and expensive.
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36. 3. Rapid Testing
The home testing antibody kits called rapid tests are cheaper
and faster, but less accurate compared to the lab testing kits.
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37. They have a specially modified paper instead of test tube
where the blood flows and gives the “one line= negative, two
lines = positive” stripes just like a home pregnancy test kit.
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38. These test kits need to be carefully designed and validated,
which is why they are not widely used yet.
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39. It is necessary that the tests are accurate and safe. Inaccurate
tests can bring great damage during this current outbreak.
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40. For some infections, one might test positive in an antibody
test, even if one is not infected.
This is because she/he might have antibodies against
something similar.
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41. And in the case of rapid tests, there is a chance of reading a
negative result as positive, since the line is hard to see.
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42. The accuracy of lab tests is far better than the rapid tests.
Accuracy can be improved in a lab by combining multiple
tests, for example, using lots of different viral fragments. But
this needs more time, equipment, and expert interpretation.
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43. (All the Governments of all Nations are striving
hard to procure the Testing kits. Let us hope for
the Good!
This is about the testing kits for COVID-19)
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46. #Stay Home
#With me
Let us be in home and kill the COVID-19.
The 3 Weapons to kill COVID-19 are:
Washing hands,
Not to touch the face and
Being in home.
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