Real-time quantitative PCR (RT-qPCR) is a widely used technique for the quantification of nucleic acid molecules, such as DNA or RNA. To perform an RT-qPCR experiment, the following key considerations should be taken into account:
Sample preparation: It is important to ensure that the sample is properly prepared and that the nucleic acid is of high quality and quantity. This may involve techniques such as DNA/RNA isolation, purification, and quantification.
Primers and probes: The choice of primers and probes is crucial for the specificity and sensitivity of the RT-qPCR reaction. Primers should be designed to specifically amplify the target gene, while probes should be designed to bind to the amplified product and generate a fluorescent signal.
PCR conditions: The PCR conditions, such as the temperature, time, and number of cycles, must be optimized to ensure that the target gene is amplified efficiently while minimizing the amplification of non-specific products.
Data analysis: RT-qPCR data should be analyzed using appropriate software and statistical methods, such as the 2-ΔΔCT method, to obtain accurate and reproducible quantification of the target gene.
Throughput: Different well formats can be significant depending on assay design and sample quantity. For varying application requirements, 96-, 96-deep-, and 384-well formats are available. An effective qPCR process includes both instrument selection and assay design. A qPCR assay should be designed from the sample preparation to assay design, taking into account each step.
Quality control: It is important to include appropriate controls and quality control measures to ensure that the RT-qPCR experiment is reliable. This may include negative controls, positive controls, and standard curves.
Standard curve: A standard curve is a plot of the log of the known amount of target (x-axis) versus the Cq or threshold cycle (y-axis). This curve is used to generate the efficiency of the PCR reaction, which is used to calculate the unknown sample.
Normalization: To compare the expression of different genes or samples, it is important to normalize the data to an internal control gene or housekeeping gene, which should be stably expressed across all samples.
Replicates: It is important to include technical replicates, which are multiple measurements of the same sample, to estimate the measurement error and the level of variability in the experiment.
Reagents: It is important to use high-quality reagents that are appropriate for the specific RT-qPCR assay. The reagents should be stored and handled correctly to ensure that they are fresh and active.
Instrumentation: The RT-qPCR instrument should be properly calibrated and maintained to ensure that the results are accurate and reproducible. It is also important to ensure that the instrument is capable of detecting the fluorescent signal from the probes.
Overall, the key considerations for running RT-qPCR experiments are sample preparation, primers and probes, PCR conditions, data analysis, quality control, normalization, replicates, reagents, and instrumentation. By taking these factors into account, researchers can ensure that their RT-qPCR experiments are reliable, accurate, and reproducible.
Read how the I.DOT Liquid Handler enables efficient and reproducible qPCR.