Microrna detection by surface plasmon resonance

Abstract

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] Lung cancer is the leading cause of cancer death in the world out of over 100 different known human cancers. Therefore there is a need for better diagnostics to improve patient outcomes. MicroRNAs are small non-coding nucleotides that have been shown to be up regulated or down regulated in cancer patients and miRNA-155 is one such microRNA whose molecular profile is up regulated in lung cancer patients. The focus of this work is to develop an effective and convenient method to detect miRNA-155 for early lung cancer diagnosis. Surface plasmon resonance (SPR) is an optical detection technique for measuring label free bio molecular interactions in real time for diverse applications. The first objective of this work was to determine the best ratio of complementary miRNA-155 to oligo (ethylene glycol) based on the SPR sensor response. This was completed by quantifying the hybridization between the complementary miRNA-155 immobilized on the surface of the sensor and 5 M miRNA-155 flowing in solution. After identifying the optimal surface chemistry ratio of 1:4 c-miRNA-155: OEG, the selectivity and limit of detection for this platform was determined. While a limit of detection of 0.002 M was determined for miRNA-155 in buffer, it was found that a more selective surface chemistry would be required to monitor miRNA-155 levels in real patient samples.