BioQuakes

AP Biology class blog for discussing current research in Biology

Tag: #tech

From Individual to Environmental: COVID-19 Antigen Testing Expands

Until recently, testing for COVID-19 has focused on the individual rather than on the environment. However, newly introduced technology promises to expand the scope of COVID-19 detection. Researchers at Washington University in St. Louis have developed an apparatus to detect the presence of the covert virus in SARS-CoV-2 without backgroundenvironmental settings. Previous attempts at this technology have been limited by the volume of air tested. Without adequate air quantity, the sensitivity of the technology is negatively impacted. The current system, however, is capable of concentrating up to 1000 m³ of air per minute, compared to the two to eight cubic meters assessed in previous attempts. The result is a system that increases viral detection sensitivity while maintaining specificity.

The newly introduced apparatus functions by using centrifugal force to approximate viral particles to a liquid matrix adherent to the wall of the test chamber. Within the matrix are found nanobodies, bioengineered antibody fragments derived from llama antibodies. As we discussed in class, the human immune system is composed of humoral and self-mediated factors. Antibodies fall into the humoral category. While human antibodies consist of a light chain and a heavy chain, llama antibodies are composed of two heavy chains. By isolating heavy chain llama antibody fragments sensitized to the COVID-19 spike protein and then splicing multiple sensitized heavy chains together, researchers were able to amplify the viral signal, in a manner similar to PCR.

While the device has yet to be approved, cleared, or authorized by the FDA, it holds promise for meaningful real-world application. For example, prior to a large public event, indoor spaces could be screened for the presence of COVID-19. If the virus were detected, remediation could be performed and the environment retested prior to the public event. In doing so, countless potential COVID-19 infections could be avoided.

This novel technology diverges from current efforts at viral detection in that it does not rely on the existence of an infected individual but rather focuses on environmental detection thereby constituting primary prevention. In the future, the technology could be applied to prevention of other infectious diseases, both viral and bacterial. Further work is needed to explore the potential application of this method.

I urge readers to respond to the above and offer opinions.

Stem Cells…Key to Youth and Controversy

Have you ever wondered what it would be like to be young forever? With the help of stem cells, this is possible. Stem cells can regenerate skin tissues and can also be used to treat diseases. However, something as enticing as living forever has its controversies. There are two types of stem cells: embryonic (ES) and adult (iPS); the embryonic stem cells are the controversial type.

Embryonic Stem Cell

Embryonic Stem Cell

The only way to effectively use the embryonic stem cell is to kill a four to six day old embryo. Some people view this act as killing a baby, which sparks ethical arguments about whether or not to utilize embryonic stem cells. To avoid this controversy, scientists have been trying to use stem cells from iPS cells instead of ES cells, but they questioned the power of iPS cells compared to the ES ones.

Because genes may differ in the iPS cells from the its source, the ES cells, there is a possibility that these two cells do not have the same capability. One scientist notes that the source of iPS and ES cells differ, which can lead to differences in gene activity. The ES cells are derived from embryos, which are not completely identical to iPS adult cells.  However, recent scientific research shows that these two types of stem cells have more equal capabilities than scientists’ initially thought.

Scientists conducted an experiment to compare the genetic makeup between the ES and iPS cell. They manipulated the male type of each cell, which eventually allowed the ES cell to transform into the iPS cell. They concluded that the iPS cells genetically matched the ES cells’ parents, and that the iPS cells had more similarities with the ES cells than iPS cells had to each other.

Even though these two experimental cells genetically matched, the two cells were not identical. The experiment showed 49 genes that differed between the two stem cells. Because of this difference, scientists needed to see if this affected the functional capability of the cells. The researchers conducted another experiment that analyzed 2 of the 49 genes. One helps take in glucose, while the other helps break it down. Even though these two genes were more active in the ES cell than the iPS cell, they were equally efficient at their respective jobs. The scientists concluded that these two specific cells were functionally equivalent.

The many experiments that have been conducted on the topic of stem cells contribute to the increase in research for more ways to utilize stem cells, without the ethical controversy. Scientists are starting to employ different technological devices, such as 3-D printers to help develop and build stem cells. This ability to fabricate cells using technology overcomes previous obstacles of limited stem cell resources.

– Source Article

– More fun facts about stem cells here

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