Quantitative PCR (qPCR)

Quantitative PCR (qPCR) represents a molecular biology technique enabling real-time quantification of nucleic acid targets through fluorescent detection during polymerase chain reaction amplification, providing accurate measurement of DNA or RNA quantities in samples. This sensitive method monitors fluorescence increasing proportionally to amplified product, determining initial target amounts through cycle threshold values where fluorescence exceeds background.

The biopharmaceutical industry extensively employs qPCR throughout research, development, manufacturing, and quality control. Gene expression studies use qPCR measuring mRNA levels assessing drug effects, biomarker validation, or pathway activation. Manufacturing quality control employs qPCR quantifying residual host cell DNA in purified biologics, detecting mycoplasma contamination, or measuring viral titres in gene therapy products. Cell line characterisation determines transgene copy numbers or verifies genetic modifications. Companion diagnostic development uses qPCR detecting mutations or expression levels predicting treatment responses. Validation demonstrates accuracy, precision, specificity, sensitivity, and reproducibility meeting regulatory requirements. Digital PCR represents newer absolute quantification method. As genomic medicine advances, viral vector characterisation needs precise quantification, and quality expectations increase, qPCR continues as an essential tool providing accurate, sensitive nucleic acid quantification.