What phase of PCR is analyzed for standard PCR?

Standard PCR analysis primarily focuses on the exponential phase of the reaction. During this phase, the amount of DNA produced doubles with each cycle, leading to a rapid increase in the quantity of the target DNA. This exponential growth is the most critical phase for quantitative assessments because it reflects the efficiency of the PCR process and the starting concentration of the target DNA.

In contrast, the stationary phase occurs when the reaction components become limiting, resulting in a plateau where the reaction no longer produces significant increases in DNA quantity. This phase is not ideal for analysis since the PCR efficiency drops and the amount of product may not reliably indicate the initial template concentration.

Other phases, such as the log phase and the declining phase, describe the behavior of DNA amplification over time but are not used for standard PCR analysis. The focus on the exponential phase is crucial for achieving accurate quantitation and ensuring that the results reflect the initial conditions of the sample.