An integrated target recognition and polymerase primer probe for microRNA detection

Area of Science:

• Biomedical Engineering
• Molecular Biology
• Analytical Chemistry

Background:

• Sensitive detection of microRNAs (miRNAs) in situ is crucial for early disease diagnosis and monitoring.
• Current methods face challenges in achieving high sensitivity, selectivity, and visual detection for intracellular miRNAs.

Purpose of the Study:

• To develop a rapid, highly sensitive, and selective biosensing strategy for microRNA detection and imaging.
• To enable accurate quantification and visualization of low-abundance miRNAs within living cells.

Main Methods:

• Utilized isothermal circular strand-displacement polymerization (ICSDP) with a double hairpin DNA probe (HP1/HP2 complex).
• The probe complex initiates polymerization upon target miRNA binding, leading to signal amplification (1:n output).
• Employed Klenow Fragment (KF) polymerase to drive the strand-displacement polymerization reaction.

Main Results:

• Achieved a low detection limit of 5 pM for miRNAs within 15 minutes.
• Demonstrated high sensitivity and selectivity, distinguishing target miRNAs from controls.
• Successfully performed in situ imaging of intracellular miRNAs within cancer cells.

Conclusions:

• The proposed ICSDP strategy offers a powerful tool for sensitive and visual detection of miRNAs.
• This method holds significant potential for early disease detection, monitoring, and intracellular miRNA analysis.