What is the difference between conventional PCR and Real time PCR?

1. Conventional PCR gives result only at the end of the reaction while Real Time PCR displays the data of amplification during the run after each cycle.

2. Real Time PCR uses a special dye which helps in production of signal with every cycle and the signal strength increases as the number of copies of the gene increase. 

3. Conventional PCR results are in the form of bands in the gel whereas in Real Time PCR Ct or threshold value gives the measure of quality and quantity of the product. 

With a Real time PCR, Detection and Amplification are done on the same instrument.

1.     Conventional PCR is more time consuming as it uses gel electrophoresis to analyze the amplified PCR products. In contrast, real-time PCR is less time consuming as it can detect amplifications during the early phases of the reaction.

2.     Real-time PCR collects data at the exponential growth phase of PCR while traditional PCR collects data at End-point of the reaction.

3.     The end point results of the conventional PCR may not be very precise, but the results of the real-time PCR are very precise.

4.     Real-time PCR is more sensitive than conventional PCR.

5.     Conventional PCR has very poor resolution while real-time PCR can detect very little changes due to the high resolution.

6.     End point detection of conventional PCR has short dynamic range while real-time PCR detection has wide dynamic range.

7.     Unlike conventional PCR, automated detection techniques are found in real-time PCR.

8.     Conventional PCR is highly sophisticated and labor intensive more than real-time PCR.

9.     Unlike real-time PCR, conventional PCR cannot discriminate between dead and live bacteria.

10.  Real-time PCR uses fluorescent dye system to detect the products while conventional PCR uses ethidium bromide and UV light to visualize bands in the agarose gel medium.

The main difference in conventional and Real Time PCR is the monitoring of amplification using DNA binding fluorescent dyes in Real Time PCR which provides quantitative data of the amount of DNA or mRNA converted to cDNA.   

Real time PCR gives relative quantitative expression on the basis of detection of DNA by a flourescent dye ie. SYBR green in REAL TIME unlike conventional PCRs wherein the results can be interpreted at the end of the PCR reaction.

Real Time PCR is a more sensitive and accurate method for analyzing the quantitative & qualitative expression of particular genes at different set of experimental conditions or  in different tissues or organisms. Conventional PCR gives qualitative expression of the presence of the gene.

In Real Time PCR, the quality of the run/amplification can be monitored during the run by analyzing the MELT CURVE and Ct values for controls and test samples whereas in conventional PCR the results can only be detected at the end of the reaction after the PCR products are loaded onto an Agarose gel with EtBr and visualized under UV light.

Real time PCR is less time consuming and labor intensive as compared to conventional PCRs. 

the main differnce between conventional PCR and Real time PCR is the analysis of results 

In conventional PCR you cannot followup the reaction at same time and you need gel electrophoresis (extra-post step) to see the results by this way also you will have negative possitive result no quantificatin results

On the other hand using real time PCR will give you chance to see the reaction followup and analysis the data on same machine giving you values.

Conventional PCR is an end-point detection method while in RT-PCR, we not only detect but have exact measurements at the time when reaction is in process.

Conventiona PCR is used to detect presence or absence of certain genomic fragments where as Real time PCR is used to detect the expression level of that fragment in the organism

Real time PCR can detect whether the reaction is running with time or not. while other did not show this result with time

 Real-time PCR collects data at the exponential growth phase of PCR while traditional PCR collects data at Endpoint of the reaction. End point detection of conventional PCR has short dynamic range while real-time PCR detection has wide dynamic range.

In conventional PCR, amplification of targeted DNA is monitored at the end of the reaction while in Real time PCR it is possible to monitor the DNA amplification quantitatively during the PCR.