Evaluation of internal standards in a competitive nucleic acid sequence-based amplification assay

Area of Science:

• Molecular Biology
• Biotechnology
• Analytical Chemistry

Background:

• Accurate quantification of microbial mRNA is crucial for diagnostics and research.
• Existing methods for mRNA detection may lack sensitivity or precision.
• Internal standards are essential for validating quantitative nucleic acid amplification assays.

Purpose of the Study:

• To develop and statistically analyze an end-point quantitative nucleic acid sequence-based amplification (NASBA) reaction.
• To evaluate the performance of two exogenous internal standards for detecting E. coli clpB mRNA.
• To assess the impact of single versus double internal standards on assay accuracy, precision, and dynamic range.

Main Methods:

• Development of an end-point quantitative NASBA assay.
• Design and utilization of two novel, rapid NASBA-generated internal standards.
• Detection using electrochemiluminescence for high sensitivity.
• Statistical analysis of accuracy and precision using linear and multiple regression.

Main Results:

• Single-standard NASBA reactions achieved >95% accuracy and >98.5% precision.
• Double-standard NASBA reactions improved accuracy to >97%.
• A dynamic range of 5 orders of magnitude was achieved with internal standards, with detection limits as low as 0.14 pg.

Conclusions:

• The developed quantitative NASBA assay with internal standards provides accurate and precise detection of E. coli clpB mRNA.
• The novel synthesis process of internal standards contributes to their high performance.
• This method offers a sensitive and robust approach for molecular quantification.