Ramification amplification-based microfluidic system for MicroRNA detection

MicroRNAs, a group of endogenous non-coding single-strand RNAs typically of 21~23nt in length, have been convincingly shown to play a critical role in a wide variety of physiological processes such as cell proliferation, differentiation, apoptosis, tumor metastasis, etc. Here we incorporated a microfluidic device with a miRNA detection method based on ramification amplification (RAM) to increase the detection throughput and reduce the labor cost. Four different reactions could be performed in a microfluidic device: (i) reverse-transcription of miRNA, (ii) annealing of circular probe (C-Probe), (iii) C-Probe ligation, and (iv) Ramification amplification. Through monitoring the intensity of fluorescent signal, tens of miRNA can be quantified in a chip in parallel. Thus, these primary results demonstrate that this new device has advantages in throughput and cost, and it might also be used for the detection of miRNA in dangerous samples, such as virus because of its automation control system.