This invention relates to the field of biomedical detection technology, and discloses a bitetrahedral framework
nucleic acid TDN
cascade amplification
system and its application, including TDN-1 and TDN-2. TDN-1 has a hairpin H1 containing a
fluorescent reporter group attached to its surface, and TDN-2 has a hairpin H2 attached to its surface. The sequences of H1 and H2 are designed to undergo an alternating hybridization
chain reaction triggered by
target mRNA. This scheme relies on the synergistic effect of TDN structural anchoring and precise hairpin probe
sequence design to overcome the technical defects of traditional free HCR hairpins in living cells, such as poor stability, low reaction efficiency, and non-specific triggering, achieving more efficient and specific
intracellular signal amplification. Furthermore, it enables highly specific and sensitive in-situ imaging and dynamic tracking of low-abundance mRNAs such as c-Myc in single living cells, effectively solving the problems of insufficient detection sensitivity and false positives caused by the inability of traditional detection methods to effectively enrich targets and the low efficiency and high background of traditional HCR and other
signal amplification technologies in
intracellular applications.