A Beginner Step-by-Step Guide for Gene Expression Analysis Using QIAcuity Digital PCR

Gene expression (GEX) is the process by which information from a gene is used to synthesize functional gene products, typically proteins, with messenger ribonucleic acid (mRNA) playing a crucial role. This process is tightly regulated to ensure genes are expressed at the right time, in the right cell type, and in appropriate amounts, which is essential for cellular function, development, and response to environmental signals. Aberrant gene expression can significantly impact cellular behavior and contribute to various diseases, making it a key area of research. Digital PCR (dPCR) offers a robust method for highly precise gene expression analysis by partitioning the PCR reaction into thousands of individual reactions, allowing for absolute quantification of nucleic acids without the need for standard curves. This method addresses several limitations of quantitative PCR (qPCR), such as the need for high PCR efficiency and susceptibility to inhibitors. dPCR's ability to accurately quantify low-abundance targets minimizes variability, artifacts, and nonreproducibility that may be observed with qPCR at low expression levels. However, qPCR remains advantageous for analyzing targets with widely different expression levels, provided that proper optimization and sample dilution are applied. Overall, dPCR offers substantial advantages for gene expression analysis, providing improved accuracy and greater resistance to inhibitors compared to qPCR. These capabilities empower researchers across diverse fields to explore gene expression hypotheses that were previously inaccessible or difficult to access using qPCR.