Method Finds Rare Proteins in Blood -- MEDICA Trade Fair

The sensitivity of detecting molecules by the new method, called FACTT, short for Florescent Amplification Catalyzed by T7-polymerase Technique, is five orders of magnitude (100,000 times) greater than that of the widely used ELISA (enzyme-linked immunoadsorbent assay).

ELISA is a common immune-system-based assay that uses enzymes linked to an antibody or antigen as a marker for picking out specific proteins. For example, it is used as a diagnostic test to determine exposure to infectious agents, such as HIV, by identifying antibodies present in a blood sample.

“The current ELISA tests can only detect proteins when they are in high abundance,” says Hongtao Zhang, PhD. “But the problem is that many of the functional proteins – those that have a role in determining your health – exist in very low amounts until diseases are apparent and cannot be detected or measured at early stages of medical pathology. It was important to develop a technique that can detect these rare molecules to detect abnormalities at an early stage.”

The FACTT technology uses a different enzyme amplification system so quantitative signals can be obtained from even a few protein molecules compared to ELISA. “The technology is remarkably adaptable to any protein and can be performed in an automated format,” notes Mark I. Greene MD, PhD, the John Eckman Professor of Medical Science. He states that the technology will soon be robotized so as to be able to screen for many rare disease-causing proteins using tiny amounts of blood.

“It is even possible that one could screen for multiple diseases at the same time and produce a precise accounting of whether disease-causing molecules are present at an early time when disease can be readily treated,” adds Greene.; Source: University of Pennsylvania School of Medicine