Enhancing Interferometry with Dolomite’s Mitos Dropix

Researchers at Vanderbilt University have developed a novel interferometry approach – the compensated interferometry reader (CIR) – and are using Dolomite’s Mitos Dropix to provide reproducible droplet production. Interferometers are widely used in science and industry for the measurement of small displacements, refractive index (RI) changes and surface irregularities. Professor Darryl J. Bornhop and his group are using this patented CIR technique in combination with a label-free, free-solution assay to measure a wide range of biomolecules and biomolecular interactions. Professor Bornhop explained: “The key difference between our approach and other interferometry methods is that we have eliminated the need for high resolution temperature control. Based on a laser, a microfluidic chip, a capillary and a CCD array, CIR enables simultaneous differential RI measurements within nanoliter volumes. By using Dolomite’s Mitos Dropix microfluidic droplet generator, we can separate two solutions for simultaneous evaluation, allowing us to discriminate between a reference and a sample to offer detection limits down to 10-7 RIU, without the added complexity of a temperature controller.” “We initially developed the CIR concept using our own, in-house microfluidic set-up, but were hindered by poor reproducibility for droplet generation. After probably a year of trying to build our own droplet generators, we heard about the Mitos Dropix, and realised that this could be just what we needed. I called Dolomite, and we got one of the first of the instruments built, becoming a beta test site. Combined with the compensated interferometric approach – looking at two windows in one capillary with a single beam – this took our sampling speed and performance to the next level.” “What makes this technique so unique is that it’s almost universal in nature; it's compatible with antibodies and antigens, DNA and RNA, small molecules, ions and proteins. We have already used the system to explore a range of biomarkers in serum and urine, and we are now working to improve the robustness and user-friendliness of the platform for applications in both drug development and clinical diagnostics.”