Universal Blood Test

Scientists from Howard Hughes Medical Institute (HHMI) have developed a method called VirScan that can detect every known human virus that is currently affecting or has previously affected a human body. The test makes use of a single droplet of blood and can act as an effective alternative to existing diagnostics in which specific set of viruses are tested.

This will help doctors in carrying out only a single test to determine the virus that has affected the individual thus saving precious time and money. The test comes with a price tag of $25. Stephen Elledge; the lead scientist of the project, said that, they have already used VirScan to screen blood samples of 569 people from US, South Africa, Thailand and Peru. The technique involves screening blood sample for antibodies against any of the 206 species of viruses known to infect humans.

When a body first encounters a specific virus it starts producing antibodies. The interesting part is that the immune system can continue producing antibodies for years or even decades after it has neutralized the virus. This helps VirScan to not only determine the present state of a body but also its past history.

The test was developed after researchers synthesised more than 93,000 short pieces of DNA, encoding different segments of viral proteins. The DNA pieces were then introduced into bacteria infecting viruses called bacteriophage wherein each bacteriophage manufactured one protein segment known as peptide and displayed the same on its surface. The peptide displayed 1000 known strains of human viruses. By sequencing the DNA of these bacteriophages, scientists can identify which viral protein pieces were grabbed onto by antibodies in the blood sample. This reveals which virus had previously attacked the body, either through infection or vaccination.