Both qfPCR (Quantitative Fluorescent PCR) and qPCR (Quantitative PCR, real-time PCR) are techniques for quantitatively measuring the amount of DNA, but they differ mainly in the following points.
1. Differences in Main Purposes and Applications
- qPCR
qPCR amplifies DNA or RNA in real time and quantitatively measures the amount of the target gene while observing the amplification process. qPCR is used for a wide range of applications including gene expression analysis, pathogen detection, and virus quantification. - qfPCR
qfPCR is specialized for the detection of chromosomal aberrations and specific gene copy number variations (CNV). It is particularly used to detect specific chromosomal copy number abnormalities (e.g., trisomy such as Down syndrome) and for prenatal diagnosis.
2. How Fluorescent Signals Are Used
- qPCR
In qPCR, the amount of amplified product produced is monitored each cycle using a fluorescent dye (e.g. SYBR Green) or a fluorescent probe (e.g. TaqMan probe). The fluorescent signal becomes stronger in proportion to the amount of amplified DNA, allowing real-time observation. - qfPCR
In qfPCR, fluorescent-labeled primers or probes that bind to specific DNA sequences are used to detect fluorescent signals after amplification. Instead of observing the amplification process in real time, the amount of amplified product is quantitatively evaluated from the intensity of the final fluorescent signal.
3. Real-time Measurement
- qPCR
qPCR enables real-time measurement because the fluorescent signal increases with each amplification cycle. This allows real-time tracking of the amount of the target gene and evaluation of amplification efficiency. - qfPCR
qfPCR is a method that measures the fluorescence intensity after amplification, rather than observing each amplification cycle. Therefore, it is not a real-time observation like qPCR, but it focuses on the final quantitative evaluation.
4. Application-specific Design
- qPCR is a general quantitative PCR with a wide range of applications and is used for highly accurate quantification of specific gene or virus levels.
- qfPCR is specialized for the detection of chromosome number and gene copy number variations and is particularly useful in prenatal diagnosis and chromosomal aberration detection, where rapid diagnostic results are required.
Conclusion
qPCR can track and quantify gene abundance in real time and is used for a wide range of genetic and expression analyses.
qfPCR is a method that ultimately measures chromosome number aberrations and gene copy number variations with fluorescent signals and is suitable for the diagnosis of chromosome aberrations and prenatal diagnosis.
Thus, qPCR and qfPCR differ in the fluorescent signal method used and the main applications, and the most appropriate technology is selected for each purpose.
