5-Apr-2023: New method of visual detection of SARS-CoV-2 can identify the infection at early stage

A new sandwich based lateral flow immunoassay (LFIA) for the detection of Receptor Binding Domain (RBD) of severe acute respiratory syndrome-coronavirus-2(SARS-CoV-2) could provide an efficient substitute for RT-PCR tests. It can detect that RBD antigen of the SARS-CoV-2 at an early stage of infection with a visual line of detection (LOD).

Popularly used gold standard techniques such as RT-PCR and ELISA are usually time-consuming, require skilled labor, specific equipment and are not feasible for on-site detection.

In order to overcome this challenge, a team of researchers from DBT-National Institute of Animal Biotechnology (NIAB) and Gandhi Medical College developed a rapid and robust platform for early and on-field detection of SARS-CoV-2 virus. A smartphone app (Color grab) has been used for the qualitative analysis of the test strip.  The developed LFIA working on the principle of antigen-antibody interaction holds the potential to be used for detection of SARS-CoV-2 without any requirement of skilled personnel and subsequently reduce the spread of the virus.

With support from Science and Engineering Research Board (SERB), an institution of the Department of Science and Technology (DST) the scientists came together to clone the gene responsible for RBD protein expression, and purify it to generate the antibody(Ab). The generated antibodies were then conjugated with monodisperse gold nanoparticles (AuNPs) to be used as a capture probe for colorimetric detection. The fabricated LFIA works in a sandwich format, where the RBD target analyte in the sample interacts with the gold nanoparticle conjugated RBD antibody to form a complex (AuNPs-Ab), which further moves along the nitrocellulose membrane and reacts with the RBD antibody coated as test line on the membrane to form a red colour band.

The RBD Ab and IgG secondary Ab were coated on the nitrocellulose membrane as test and control, respectively to test the presence of antigen (Ag) in the sample. Further, the excess antibody bonded with the control line coated with secondary IgG antibody validating the functionality of the test strip. An absorbent pad was placed at the end of the strip to prevent backflow across the strip.

The presence of band colour at test and control line indicates a positive result whereas a single line in control indicates a negative result. Depending on the target analyte, various parameters such as blocking buffer, antibody conjugation concentration, and antibody coating concentration on the membrane have been optimized to obtain band color with maximum binding efficiency. The band intensity of the test line was analysed using a simple smartphone-based application for image acquisition and analysis of the test line color, which can split any color data into its three primary color components -- red, green, and blue (RGB data). The specific color component shows the trend of increasing or decreasing intensity of color. This study was published in the Journal of Medical Virology recently.

The developed LFIA strips can be useful as a portable, point of care device (PoC) for on-site detection of SARS-CoV-2 particularly at  home or even in rural areas. Moreover, the cost of LFIA strips is much less as compared to standard RT-PCR test making it a more economical option for people who cannot afford the RT-PCR test.

India achieves a milestone of more than 15 thousand transplants in a year for the first time in 2022

It was stated by Health Secretary Rajesh Bhushan during the National Organ and Tissue Transplant Organisation Scientific Dialogue 2023 on February 19.

This achievement indicates an annual increase of 27% in transplant numbers, and reflects the positive outlook of the country in organ and tissue transplants. The Health Secretary attributed the fast resurgence in transplant activities post-COVID to programmatic restructuring, communication strategy, and professional skilling as the top priority areas.

Organ and tissue transplants have emerged as a ray of hope for patients suffering from organ failure or tissue damage. These transplants are life-saving procedures that involve replacing a diseased, damaged or missing organ or tissue with a healthy one from a donor.

In recent times, the advances in medical technology and the increased availability of organ donors have led to an increase in the number of successful organ and tissue transplants. However, there is still a significant shortage of donor organs, which leads to a long waiting time for patients who need them.

Organ transplants:

Organ transplants refer to the surgical procedure of replacing a diseased or damaged organ with a healthy one from a deceased or living donor. The most commonly transplanted organs include the heart, kidneys, liver, lungs, and pancreas.

Major Organ Transplants:

Organ	Transplant Procedure
Kidney	Kidney transplants are the most common type of organ transplant, as the kidney is the most frequently donated organ. The procedure involves removing a kidney from a living or deceased donor and transplanting it into the recipient. The success rate of kidney transplants is high, and the recovery time is relatively short.
Liver	Liver transplant is a complex procedure that involves the removal of a diseased liver and replacing it with a healthy one from a deceased or living donor. This procedure is recommended for patients suffering from severe liver damage due to cirrhosis, cancer, or other diseases.
Heart	Heart transplant is a life-saving procedure for patients with end-stage heart failure. It involves the removal of a diseased heart and replacing it with a healthy one from a deceased donor. The success rate of heart transplants has improved significantly in recent years due to advancements in surgical techniques and immunosuppressive drugs.
Lung	Lung transplant is recommended for patients with end-stage lung disease, such as chronic obstructive pulmonary disease (COPD) or pulmonary fibrosis. The procedure involves removing the damaged lung and replacing it with a healthy one from a deceased donor.

 

Tissue Transplants:

Tissue transplants refer to the surgical procedure of transplanting healthy tissues from a donor to a recipient. The most commonly transplanted tissues include cornea, bone, skin, and heart valves.

Major Tissue Transplants:

Organ	Transplant Procedure
Cornea	Cornea transplant is a common procedure that involves replacing a damaged or diseased cornea with a healthy one from a deceased donor. The procedure is usually performed under local anesthesia, and the recovery time is relatively short.
Bone	Bone transplant is recommended for patients with bone injuries, fractures, or diseases such as osteoporosis. The procedure involves transplanting healthy bone tissue from a deceased donor to the recipient.
Skin	Skin transplant is recommended for patients with severe burns, skin injuries, or diseases such as skin cancer. The procedure involves transplanting healthy skin tissue from a deceased donor to the recipient.
Heart Valve	Heart valve transplant is recommended for patients with heart valve diseases such as stenosis or regurgitation. The procedure involves replacing the damaged heart valve with a healthy one from a deceased donor.

The success rate of transplant procedures have improved significantly in recent years, but there is still a significant shortage of donor organs. Therefore, it is essential to raise awareness about organ donation and encourage people to become organ donors. With increased awareness and availability of donor organs, we can save many lives and make a significant impact in the field of medical science.