ANNEALING OF OLIGONUCLEOTIDE HAIRPINS AS EFFECTIVE APPROACH TO IMPROVE THE ANALYTICAL CHARACTERISTICS OF AMPLIFICATION METHOD FOR MICRORNA DETERMINATION BASED ON CATALYTIC HAIRPIN ASSEMBLY REACTION

This work presents a new approach for reducing the background reaction of the catalytic hairpin assembly (CHA) amplification method, based on optimizing the conditions for annealing of hairpin oligonucleotide probes. This approach made it possible to improve the analytical characteristics of the amplified CHA-based method for microRNAs quantitation.

A selective, inexpensive probe for UV-induced damage in nucleic acids

Absorption of UV light by nucleic acids can result in the formation of molecular lesions in DNA and RNA, leading to mutagenesis, carcinogenesis, and cell death. In this work, hairpin oligonucleotide probes, which have previously been shown to be selective for DNA damage, are used. The hypochromic effect, which arises from the formation of the target–hairpin hybrid when there is no damage, is used to measure the amount of UV damage by measuring the amount of single-stranded DNA oligonucleotides. With accumulated UV exposure, the target–hairpin hybrid concentration decreases and the absorbance increases, enabling detection of UV-induced DNA damage. Our results show that the selectivity for DNA damage of the hypochromism probe is comparable with the molecular beacon probes, detecting between one and three lesions in an oligonucleotide. In addition, this probe is more than 10 times cheaper than molecular beacon probes. However, it shows lower sensitivity to DNA damage. This makes its use recommended for high-throughput, qualitative analysis of DNA damage. This introduces a simple, fast, mix-and-read assay for the detection of DNA damage.