Nucleic acids detection using cationic fluorescent polymer based on one-dimensional microfluidic beads array

An assay for rapid and direct detection of DNA/mRNA using cationic fluorescent polymer based on one-dimensional microfluidic beads array (1-D chip) has been developed. The cationic water-soluble polythiophene derivatives can easily transduce hybridization events into measurable optical signal due to the conformational changes of the conjugated backbone, when mixed with single-stranded or double-stranded oligonucleotides. In this paper, the polymer was introduced into 1-D chip for fluorescence detection of nucleic acids, and demonstrated its capability on rapid detection of p53 complementary DNA (cDNA) with different concentration. Using this system, we have evaluated the mRNA expression changes of three tumor-associated genes (p53, c-myc and cyclin-d1) in human nasopharyngeal carcinoma CNE2 cell lines before and after 5-flouorouracil (5-FU) stimuli. These results were validated by the conventional reverse transcriptase-PCR. The most important advantage of this assay is not needed target or report labeling prior to hybridization, which makes the experiment process easy to handle and low-cost for multi-target measurement.