An Asymmetric Stem-Loop Translator Enhances Specificity of One-Pot Isothermal CRISPR/Cas12a Assay

Area of Science:

• Biotechnology
• Molecular Biology
• Diagnostics

Background:

• CRISPR-based assays are crucial for diagnostics but often lack specificity.
• Nonspecific activation and cross-reactivity limit current CRISPR assay performance.

Purpose of the Study:

• To develop a highly specific and sensitive CRISPR-Cas12a assay using an asymmetric stem-loop translator.
• To create a versatile, one-pot isothermal platform for nucleic acid and small-molecule detection.

Main Methods:

• Integrated one-pot isothermal strand displacement amplification (SDA) with CRISPR/Cas12a.
• Utilized an asymmetric stem-loop translator for precise molecular recognition and signal transduction.
• Optimized reaction parameters to mitigate enzyme inhibition and aerosol contamination.

Main Results:

• Achieved highly specific and sensitive microRNA (miRNA) detection with a 500 fM limit of detection.
• Successfully distinguished single- and double-base mutations.
• Demonstrated adaptability by detecting aflatoxin B1 using an aptamer-based recognition element.

Conclusions:

• The asymmetric stem-loop translator significantly enhances CRISPR/Cas12a specificity.
• The developed platform offers a generalizable framework for rapid nucleic acid and small-molecule diagnostics.
• The assay is suitable for clinical and point-of-care settings due to its sensitivity, specificity, and modularity.