With one drop of blood new test could diagnose myriad of conditions from cancer to diabetes

A new blood test could one day analyze one drop of blood to detect a host of diseases, from cancer to autoimmune conditions.

Scientists at the University of Pittsburgh, United States (U.S.) have developed a unique method for detecting antibodies in the blood of patients.

Their discovery marks a proof-of-principle concept, that could open the door to the development of simple diagnostic tests for diseases for which no microbial cause is known.

The findings mark the first evidence that it is possible to develop blood tests for any infectious disease by screening random libraries of non-biological molecular shapes.

The study, which was funded by the Bill and Melinda Gates Foundation, is published in the Journal of Immunological Methods.

Dr. Donald Burke, dean of the Pitt Graduate School of Public Health, said: “This ‘needle-in-a-molecular haystack’ approach is a new way to develop diagnostic assays. The method does not rely on starting with known viral components.

“This is important because there are conditions for which there isn’t a known antigen, such as newly emerged epidemics, autoimmune diseases or even responses to traumatic injury.”

When a person’s immune system is faced with an antigen or foreign invader, such as an infectious disease, or even an injury with tissue damage, it responds by producing antibodies.

Like the pieces of a puzzle, specific parts of the surface of these antibodies fit to the shape of the molecules on the invader or the damaged tissue.

The researchers used a technique, pioneered by co-author Dr. Thomas Kodadek, of the Scripps Research Institute.

It synthesizes random molecular shapes called ‘peptoids’ hooked on to microscopic plastic beads. The technique can produce millions of molecular shapes.

The peptoids are not organic, but if they match to the corresponding shape on an antibody, that antibody will connect to them, allowing the scientist to pull out that bead and examine that peptoid and its corresponding antibody.