Hybridization Chain Reaction (HCR) is a breakthrough molecular technology revolutionizing the fields of biological research and diagnostics. HCR involves using DNA or RNA probes to trigger chain reactions, producing long DNA/RNA polymers without enzymes. When target genetic sequences are present, these probes hybridize, initiating a cascade of hybridization events forming detectable signals. HCR is highly sensitive and specific, enabling the identification and quantification of nucleic acids with remarkable accuracy. It’s particularly valuable for detecting low-abundance targets in complex samples, such as cancer biomarkers or infectious agents. As HCR continues to evolve, it promises to enhance early diagnosis and personalized medicine significantly.