What Is QPCRqPCR (quantitative polymerase chain reaction) is a widely used molecular biology technique, evolving from the initial polymerase chain reaction (PCR) pioneered in the 1990s. The PCR technique, despite its popularity in the 1990s, did not provide data that allowed scientists to identify the amount of pathogen in the sample. qPCR developed from this and added versatility and flexibility to this process, providing far more information to scientists.

So what is qPCR?

Put simply, qPCR is a form of 'molecular photocopying'. qPCR is a laboratory-based technique used to amplify and target a DNA molecule in a given sample. This method quantifies the amount of specific DNA in samples such as blood, tissue or cells collected on a swab.

qPCR is used for DNA fingerprinting, the pinpointing of genetic disorders and for the detection of both bacteria and viruses; in fact, qPCR has led the way in diagnostic testing for AIDS.

Some laboratories no longer offer conventional PCR techniques for diagnostic work, now only using qPCR as it has several benefits over and above PCR such as:

1. The ability to quantify the amount of pathogen (whether viral or bacterial) in a sample, rather than just highlighting whether it is present or not

2. qPCR dramatically reduces the potential for false positive results that can be attributed directly to the 'closed tube' system used in qPCR

3. qPCR has a far quicker turnaround time and a higher sample testing throughrate, meaning the time between receiving and testing the sample and delivering the report is dramatically reduced

Challenges of using qPCR

qPCR is a sophisticated and accurate diagnostic technique driven by the need for lower costs and increased throughput of sample and more reliable data. However, there are challenges to qPCR:

1. Scientists still face the hurdle of false positive test results, although the instances of this happening with qPCR are vastly reduced

2. qPCR requires specialist instruments as well as increased knowledge required to interpret the data; it takes time for scientists to be able to use qPCR techniques

3. The use of specialist equipment means that the setting up and purchasing of the equipment for some smaller laboratories can be prohibitive. This of course can also mean that some developing countries do not have the finance to invest in such an advanced technology

qPCR is a scientific technique with far reaching ability in the modern world and its benefits mean that it looks like growing in importance in the future.

Article written by Jack Fortune representing a company who provide detailed information on qPCR amongst their services - www.primerdesign.co.uk.