September 19, 2011
Bioengineering Assistant Professor Amy Herr, along with graduate student Kelly Karns, has developed a microfluidic assay which can test tears for proteins that signal disease.
Tears are not routinely used for clinical testing because they are alkaline, and do not adhere predictably to antibody-coated surfaces. The Herr Lab assay does not require any surface participation, instead mixing tears with fluorescently-labeled antibody in an 80-micrometer wide channel on polyacrylamide gel. An electric field causes proteins of different sizes to move at different rates along the gel, which will allow a fluorescent microscope to quantify the tear protein by the appearance of the distinct visible band produced.
The researchers were able to detect the protein for Sjögren’s Syndrome, an autoimmune disease, in under 5 seconds using less than a microliter of tear blotted from a patient’s eye.