QUALITY

QUALITY estimates viral copy numbers from polymerase chain reaction-based limiting dilution assays (PLDAs) using a statistical optimization approach to improve accuracy and standardize quantification for targets such as human immunodeficiency virus (HIV).

Key Features:

• Poisson-based expectation: Uses a Poisson probability distribution to calculate expected negative reactions at each dilution.
• Optimization of fit: Estimates copy number by maximizing the goodness of fit between observed negative reactions and Poisson-expected negatives.
• Chi-squared statistic: Employs the chi-squared (χ²) statistic to determine the best-fit copy number.
• User-defined error probabilities: Incorporates user-specified false-positive and false-negative PCR probabilities into the estimation process.
• Simulation validation: Validated through simulations across varying numbers of PCR amplifications per dilution and different dilution factors.
• Assay efficiency strategy: Proposes strategies for conducting more efficient assays to optimize resource use and assay performance.

Scientific Applications:

• Viral quantification from PLDAs: Quantifying viral copy numbers from polymerase chain reaction-based limiting dilution assays (PLDAs).
• HIV measurement: Estimating human immunodeficiency virus (HIV) copy numbers in biological samples.
• Standardization: Standardizing estimation to reduce inter-laboratory variability in limiting-dilution analyses.
• Assay design optimization: Informing dilution and amplification scheme design to improve assay precision and efficiency.

Methodology:

Estimates copy number by optimizing the fit between observed negative reactions and expected negatives calculated from a Poisson probability distribution, using the chi-squared (χ²) statistic to select the best-fit value, while incorporating user-defined false-positive and false-negative PCR probabilities; validation was performed by simulation across different numbers of PCR amplifications per dilution and varying dilution factors.