Ultrasensitive Detection of Gastric Cancer Plasma MicroRNAs via Magnetic Beads-Based Chemiluminescent Assay

Rapid, sensitive and minimally invasive biomarker assays for early detection of health events and effective clinical management of cancer are urgently needed to reduce high morbidity and mortality from cancer. These assays may allow better clinical decision and more efficient use of health systems. It is reported that aberrantly expressed microRNAs (miRNAs) are observed in gastric cancer blood plasma and these miRNAs might serve as early detection biomarkers for this malignancy. Current methodological approaches for miRNAs analysis are not satisfactory and suffer from inherent limitations, such as poor sensitivity and laborious handling procedures. In this study, an integrated protocol based on magnetic beads (MBs) and chemiluminescence (CL) technique was developed for rapid and sensitive detection of miRNAs from gastric cancer plasma. Factors that may influence the chemiluminescent signal were also systematically investigated and optimized. This technique revealed an ultralow limit of detection of 0.1 pM, at extraordinarily wide range of six orders of magnitudes. Moreover, the avoidance of potential bias in the reverse transcription polymerase chain reaction (RT-PCR) that may influence the accuracy makes this method suitable and effective for biomarkers detection.