Curcumin - a natural colorant-based pH indicator for molecular diagnostics.

Area of Science:

• Biotechnology
• Molecular Diagnostics
• Natural Product Chemistry

Background:

• Loop-mediated isothermal amplification (LAMP) is a sensitive DNA amplification technique.
• LAMP generates acidic byproducts, enabling pH-based detection.
• Visual detection methods are crucial for point-of-care diagnostics.

Purpose of the Study:

• To develop a rapid, visual, and cost-effective method for detecting bacterial DNA using LAMP.
• To evaluate curcumin as a natural pH indicator for LAMP.
• To identify specific bacterial pathogens, Staphylococcus aureus and Streptococcus pneumoniae.

Main Methods:

• DNA amplification using loop-mediated isothermal amplification (LAMP).
• Utilized curcumin as a colorimetric pH indicator.
• Optimized reaction conditions for sensitivity and speed.
• Visual color change detection (red to yellow) for positive results.

Main Results:

• Curcumin showed a distinct color change from red (negative) to yellow (positive) within 30 seconds.
• Achieved high sensitivity: 10 fg μL-1 for S. aureus and 1 pg μL-1 for S. pneumoniae.
• Demonstrated the effectiveness of curcumin for on-site diagnostics.
• The method proved adaptable for both laboratory and field settings.

Conclusions:

• Curcumin is an effective, natural pH indicator for colorimetric LAMP assays.
• This method provides a rapid, visual, and sensitive approach for pathogen detection.
• The developed technique offers a practical alternative to conventional methods for infectious disease diagnostics.