Real Time Polymerase Chain Reaction (PCR real time) testing is used to detect whether specific DNA or RNA gene sequences are present in tissue, and if so how many. PCR real time methods are faster and usually more accurate than traditional PCR testing, making PCR real time methods more attractive where feasible.

PCR real time methods are an evolution of traditional PCR testing - PCR real time testing relies on amplification of small quantities of test DNA in the same way as more traditional methods. PCR real time methods thus share the fundamental benefit of being useful for investigating very small samples of material. This also constitutes the most fundamental concern with PCR real time testing methods - practitioners undertaking PCR real time tests must guarantee against PCR real time tests being contaminated, as results could become easily and drastically flawed.

PCR real time testing differs from other PCR methods in that PCR real time tests quantify copy DNA or messenger RNA sequences after each amplification round – this being the real time element of the name ‘PCR real time’. PCR real time tests work on the principal that the greater the number of sequences, the sooner they will become apparent. It is this fundamental assumption that results in the very sensitive nature of PCR real time testing.

PCR real time tests generally rely on the addition of either a fluorescent dye or an oligonucleatide which cause fluorescence of certain gene sequences, enabling PCR real time testers to observe and quantify gene sequences (PCR real time tests are often prefixed 'quantified').

PCR real time tests are used in an increasingly diverse range of ways – PCR real time tests can be used in labs or in situ, to identify the presence of infectious diseases or cancers etc. PCR real time methods are also very commonly used in research laboratories to investigate the gene expression characteristics of bacteria. Other applications of PCR real time technology include investigating germination cycles and other agricultural phenomena.

LSL