Ralph Weissleder, Harvard Medical School, Boston, Massachusetts, USA, and colleagues have built on earlier work in handheld cancer detection systems using microfluidics to develop a related device that can quickly and easily detect pathogenic bacteria. The device can detect worrying strains that have developed resistance to common antibiotics, such as methicillin resistant Staphylococcus aureus (MRSA), and Mycobacterium tuberculosis (TB).
The team describes the system as “sensitive and robust” and emphasizes that it requires no bacterial isolation or culture growth to work, thus allowing rapid diagnostics to be carried out. The detector uses polymerase chain reaction (PCR)-amplified mycobacterial genes. These are sequence-specifically tagged by magnetically-labeled microspheres. NMR spectroscopy is used as the detector for the tagged genes and the whole system is integrated on a small microfluidic cartridge, which is not much bigger than a standard laboratory microscope slide. A sputum sample from a patient suspected of being infected with TB is all that is needed and analysis takes a mere 2.5 hours. The presence of genes from other microbes does not interfere with detection of TB.
- Magnetic barcode assay for genetic detection of pathogens,
Monty Liong, Anh N. Hoang, Jaehoon Chung, Nil Gural, Christopher B. Ford, Changwook Min, Rupal R. Shah, Rushdy Ahmad, Marta Fernandez-Suarez, Sarah M. Fortune, Mehmet Toner, Hakho Lee, Ralph Weissleder,
Nat. Commun. 2013, 4, 1752.
Also of interest:
- Handheld cancer detection: Microfluidics meets NMR,
SpectroscopyNOW.org 2013, June.