Biomarkers are an exciting part of medical research--they must be, otherwise you wouldn't be reading this story. But finding them in tissues, blood and other body fluids isn't always easy, especially at low levels, and can involve tricky and time-consuming purification steps. Using magnetic particles tagged with antibodies in a fast, simple, one-step assay could make this a whole lot easier.
Dutch researchers from Philips Research and Eindhoven University of Technology created magnetic nanoparticles (particles less than around 100 nanometers in diameter) and coated these with antibodies directed to specific protein biomarkers. The test took only 14 minutes to detect very low levels of the protein prostate cancer biomarker PSA (prostate-specific antigen) straight from human plasma with no preparation or dilution needed. Existing tests for PSA can take hours and are not as sensitive.
The test uses two antibodies that link with different parts of the PSA molecule. The magnetic pulses line the rods up, helping them to link with the PSA at very low levels, and the size of the clusters indicates the levels of PSA.
The researchers used PSA to demonstrate the technique--it could have potential in a range of diagnostics. Its level of sensitivity could allow physicians to detect biomarkers at low levels and therefore find disease at an early stage, or could help researchers to find new low-level biomarkers that could be targets for treatment or new diagnostics.