Which scientific process is often used in gene expression studies?

In gene expression studies, reverse transcription to synthesize complementary DNA (cDNA) plays a crucial role. This process involves converting RNA into DNA, which is essential since mRNA serves as the template reflecting the gene expression level in a cell. By synthesizing cDNA from mRNA, researchers can analyze gene expression more effectively.

This step is critical because cDNA can be amplified and quantified to determine how much of a particular mRNA is present in a sample, which directly correlates with gene expression levels. Subsequent techniques, such as quantitative PCR, often utilize this cDNA to assess expression levels more accurately.

While other methods like polymerase chain reaction (PCR) are related and important in molecular biology, they are typically used to amplify DNA rather than to measure gene expression directly. Other options like Western blotting focus on protein detection, and gel electrophoresis is mainly used for separating DNA, RNA, or proteins but does not provide direct information on gene expression levels. Hence, reverse transcription to synthesize cDNA is a foundational process for studying gene expression in detail.