Exonuclease. and Gold Substrate Capturing Cyclic Strategy for Detection of Manganese Superoxide Dismutase DNA

A sensitive and simple method was developed for detection of manganese superoxide dismutase ( MnSOD) DNA using exonuclease. assisted signal amplification technique and gold substrate capture cycle strategy. This strategy relied on three major steps in the experiment. First, the hairpin probe labeled with fluorophore was opened by MnSOD DNA. Second, with the help of exonuclease., the hairpin probe was partially hydrolyzed to release MnSOD DNA and residual hairpin probe fragments labeled with fluorophore. The released MnSOD DNA could be recycled and continued to hybridize with the complete hairpin probe. And third, the reaction solution contained a large number of residual hairpin probe fragments labeled with fluorophore, which could be hybridized with capture probe modified on gold substrate, and then transferred to a new tube solution for fluorescence detection. Based on this principle, the method for MnSOD DNA detection was constructed, with detection limit of about 0. 42 pmol/ L. The method was also applied to the detection of MnSOD DNA in lysates of HeLa, Jurkat and Ramos cells, with recoveries ranging from 90. 2% to 111. 2%. This method could effectively eliminate the influence of background interference and matrix effect, and provide a new promising paradigm in developing universal methods for detection of short DNA.