Single-stranded nucleic acid for real-time detection of genetic variation of single target gene and detection method using the same

A single-stranded nucleic acid, which is for real-time detection of a genetic variation of a single target gene,

• the single-stranded nucleic acid comprising:
• (i) a structure of X-Y-Z;
• (ii) a complementary bonding to all or part of the nucleotide sequence of a single target gene containing a genetic variation;
• (iii) at least two identical or different detectable markers attached to both ends or the inside thereof;
• and
• (iv) the Y region being an RNA having a genetic sequence of one or two nucleotides at a locus of the single target gene and being cut out by a cleavage enzyme when hybridized with the single target gene,
• wherein when the genetic variation of the single target gene is single nucleotide polymorphism (SNP), then the single-stranded nucleic acid has the X region being a DNA having a genetic sequence of 4 to 20 nucleotides and the Z region being a DNA having a genetic sequence of 4 to 20 nucleotides, both the X and the Z region being separated from the single target gene when the Y region is cut out by a cleavage reagent following hybridization of the single target gene and the single-stranded nucleic acid,
• wherein when the genetic variation of the single target gene is single nucleotide polymorphism (SNP), point mutation, or miRNA isoform, then the single-stranded nucleic acid has the X region being a DNA having a genetic sequence of 10 to 30 nucleotides and the Z region being a DNA having a genetic sequence of 1 to 5 nucleotides, the Z region other than the X region being separated from the single target gene when the Y region is cut out by a cleavage reagent following hybridization of the single target gene and the single-stranded nucleic acid, thereby allowing the single-stranded nucleic acid to act as a primer and a probe at once.