Highly sensitive detection of biomarkers using magnetic modulation biosensing: an improvement over flow cytometry (Conference Presentation)

Abstract

Luminex 200 is a flow cytometer that is widely used to detect very small concentrations of biomarkers. For biomarkers detection, fluorescently labeled probes and magnetic beads are attached to target molecules. After several washing and separation steps to remove unbound fluorescent molecules, single magnetic beads pass one by one through a narrow channel and their fluorescent signal is measured. Previously, we presented a novel magnetic modulation biosensing (MMB) system, which provides very high sensitivity in biomarkers detection. Unlike the particle by particle approach of flow cytometry, the MMB system is based on aggregating the magnetic beads and manipulating them in and out of the excitation laser beam. The modulation separates the signal from the background noise without washing steps. Using the MMB platform, we were able to detect Interleukin-8 with a limit of detection of 0.04 ng/L. Here, we provide a head-to-head comparison of the MMB platform and the Luminex 200 instrument. Comparisons were performed by processing identical bead-based tests in both systems. Using Luminex Triple Dye Beads, we showed that the MMB has at least 2x better sensitivity than the Luminex 200. In addition, we used a cardiac Troponin I assay and showed that the MMB has 10x better sensitivity than the Luminex 200. While the Luminex 200 has multiplexing capabilities, the MMB system provides higher sensitivity and a washless protocol that facilitates the use of the platform in point of care applications.