Detection of Mycobacterium tuberculosis
Mycobacterium tuberculosis is still one of the most prevalent causes of infectious disease on a global scale and is far more common in regions with less developed and disseminated health care. One way to address this acute problem is to provide diagnostic testing equipment that is cheap, fast and easy to handle. We are running a bilateral project focused on development of methods and equipment for simplified diagnostics of the acute phase of tuberculosis, when the risk of spreading the infection to healthy individuals is high. The project includes a partner in India that is developing the antibodies and reagents needed for the specific detection of M. tuberculosis.
A diagnostic instrument for detecting M. tuberculosis in the doctor’s office
Our intention is to develop a system that will enable diagnostics performed in field conditions by unskilled personnel. It would replace conventional microscopic analyses, which are normally not available in areas most affected by the disease. An efficient and disseminated diagnostic service, in combination with immediate treatment, can limit the spread of the disease and eventually improve the health as well as the economy of the affected regions. The goal of this project is to deliver a prototype instrument and reagents that would enable the specific detection of M. tuberculosis in sputum samples with a sensitivity in the range of 100-1000 bacteria/ml.
Biosensor system based on thermally-blocked magnetic nanoparticles
An ideal biosensor would detect target molecules directly without the use of labeled ligands or multiple washing steps. We have overcome these obstacles by designing a sensor system based on magnetic nanoparticles with a surface modified to bind virtually any specific molecule. When target molecules such as antibodies are bonded to the particles, the hydrodynamic particle volume increases:the more target molecules that get stuck on the magnetic particles, the larger the particles. This increase in particle size can be determined by using dynamic magnetic measurements in a procedure we have developed and patented.
We have also developed an instrument capable of measuring the frequency dependent magnetic susceptibility of nano-particle systems and empirically finding a good correlation between antibody concentration in a sample and the observed change in hydrodynamic volume of antibody-binding magnetic particles. The technique can be used for a wide variety of analyses with biological applications. Detecting disease markers in patient samples is one application; others could be analyzing environmental samples or monitoring chemical reactions or synthesis in the chemical and biochemical industries.