CRISPR-dCas9 based DNA detection scheme for diagnostics in resource-limited settings.

Area of Science:

• Molecular Biology
• Biotechnology
• Medical Diagnostics

Background:

• Nucleic acid detection is vital for research and medical diagnostics.
• Current DNA detection methods are often inaccessible in resource-limited settings due to high costs and complex requirements.
• There is a need for simple, field-deployable DNA diagnostic tools.

Purpose of the Study:

• To develop an isothermal DNA detection scheme for diagnosing pathogenic DNA in resource-limited settings.
• To create a low-cost, instrument-free diagnostic tool for point-of-care applications.
• To demonstrate the adaptability of the method for detecting various DNA targets.

Main Methods:

• Developed instrument-free DNA extraction from urine and blood samples.
• Utilized Recombinase Polymerase Amplification for rapid DNA amplification (<10 copies in 15 minutes).
• Employed CRISPR-dCas9/sgRNA and Rolling Circle Amplification for signal amplification, leading to a colorimetric readout.

Main Results:

• Achieved high sensitivity (<10 DNA copies) and speed (<15 minutes) for amplification.
• Demonstrated successful detection of parasite DNA in buffer at 23 °C with zeptomole sensitivity.
• Validated the method with a colorimetric readout visible to the naked eye using spiked blood samples.

Conclusions:

• The developed isothermal DNA detection scheme is effective for diagnosing pathogenic DNA in resource-limited settings.
• The method's simplicity, low cost, and portability make it suitable for point-of-care diagnostics.
• The guide-RNA programmability allows for versatile adaptation to detect a wide range of DNA targets.