Written by the Fiveable Content Team • Last updated August 2025
Written by the Fiveable Content Team • Last updated August 2025
Definition
Real-time PCR (Polymerase Chain Reaction) is a laboratory technique used to amplify and simultaneously quantify a targeted DNA molecule. It allows for the detection and quantification of nucleic acids in real-time during the amplification process.
AP course connection
Topic 12.2: 12.2 Visualizing and Characterizing DNA, RNA, and Protein
Real-time PCR utilizes fluorescent dyes or probes to monitor the accumulation of the amplified product during each cycle.
It can be used for both qualitative and quantitative analysis of DNA and RNA.
The two main types of real-time PCR are SYBR Green-based and probe-based assays (e.g., TaqMan).
A key advantage of real-time PCR over traditional PCR is its ability to provide quantitative data that correlates with the initial amount of template DNA or RNA.
Real-time PCR requires careful optimization of reaction conditions, including primer design, to ensure specific and efficient amplification.
Related terms
SYBR Green: A fluorescent dye used in real-time PCR that binds to double-stranded DNA.
TaqMan Probe: A sequence-specific probe labeled with a fluorescent reporter dye used in real-time PCR for detecting specific DNA sequences.
Ct Value: Cycle threshold value; the number of cycles required for the fluorescent signal to exceed a defined threshold in real-time PCR.