Plausible fast & economic detection of SARS-CoV infection 1 using paper-based isoelectric focusing: a hypothesis

6 In the wake of current pandemic of COVID-19, there has arisen an urgent need to come up 7 with novel ways to detect the infected person with SARS-CoV-2 at an extremely fast pace so 8 that the person is immediately quarantined to prevent further transmission of the virus to 9 other susceptible individuals. Such quick detection measures would allow the timely 10 mitigation of the dreadful disease which has claimed close to 100,000 lives worldwide. In this 11 article, a very fast and cheap way to detect the presence of SARS-CoV in the biopsied tissue 12 has been proposed. The current method discussed here would drastically reduce the time of 13 detection of an infected person to less than ~ 6 hours in addition to the economic benefit of 14 using paper-based isoelectric focusing. The infecting coronavirus that causes severe 15 respiratory distress contains four major types of structural proteins: spike (S) proteins, 16 membrane (M) proteins, envelope (E) proteins & nucleocapsid (N) proteins. Peculiar 17 isoelectric points of these four structural proteins have been proposed to detect the SARS-18 CoV infection. This work would be of immense interest to the scientists, researchers as well 19 as health professionals who are trying to mitigate the spread of the disease as well as to cure 20 it at the same time.


Introduction
With the spread of the fatal COVID-19 that has become a pandemic, researchers worldwide are trying to accelerate the detection as well as treatment regimens of the zoonotic coronavirus-related disease.The disease is caused by a family of virus, known as Coronavirus, causing the acute respiratory distress in the patients.Thus, the disease that is caused by such virus is known as Severe Acute Respiratory Syndrome abbreviated as SARS.
This virus is known to contain four major structural proteins, spike (S) proteins, membrane (M) proteins, envelope (E) proteins & nucleocapsid (N) proteins that are spatially arranged and distributed within the spherical virus particle, as shown in the schematic in Fig. 1.

Virus purification from cell lysate [8]
• Sample containing the virus would be subjected to hypotonic burst using 5 ml of double distilled water following 15 minutes incubation at room temperature.The cell debris would be separated from the infecting virus particles by centrifuging the lysate at 3000×g for 15 minutes.The resulting supernatant would be containing the virus particles that would further be removed by pipeting and mixing with equal volumes of 2× DMEM containing 4% FCS, 2% penicillin-streptomycin solution, and 4 mM Lglutamine for restoration of the tonicity as in case of the original virus stock.
• Alternatively, viruses can also be collected from the breath samples of the suspected individuals infected with coronavirus [9].The virus samples could be collected using simple breath-analyzer tools that are regularly used by law-enforcing agencies to check drunk driving cases.

Separation of viral capsid proteins from viruses [10]
• Virus particles have been reported to degrade at pH 10.5.Using the mentioned protocol in the reference therein, the viral capsid proteins would be separated for further analytical procedures.

Paper-based isoelectric focusing [11]
• The setup for paper-based would be prepared using the materials & methods described in the reference therein.The separation of viral capsid proteins would take ~2 hours if the applied focusing voltage was kept at 500 V whereas the time of pI-

Discussion
The above discussed method to analyze the sample collected from the diseased person for SARS-CoV infection provides a novel way to detect such infections.This analytical tool is extremely time-efficient (takes less than ~ 6 hours) and cost-effective in comparison to currently employed techniques that require DNA polymerases, specific DNA primers that would complement the genetic sequence of the infecting virus.In the proposed method, the viral capsid proteins could be detected just on the basis of their respective isoelectric points with pI values of M & N structural proteins in the very peculiar range (pI > 9).This range is extremely uncommon in common histological samples, thus would become a unique signature for the presence of SARS-CoV in the analyzed sample.This work would be of immense interest to the scientists, researchers as well as health professionals who are working towards the mitigation of the dreadful respiratory viruses, especially in the wake of current pandemic COVID-19.

Fig. 1 Table 1
Fig. 1 Schematic diagram of the SARS-CoV is shown, depicting the spatial arrangement of various structural proteins [1].