Polymerase Chain Reaction Test (PCR Test): is an analysis in which small parts of deoxyribonucleic acid (DNA) or ribonucleic acid (RNA) are amplified in order to help analyze a short sequence of DNA or RNA even in samples containing a small amount of DNA, as countless copies of DNA can be produced, and it takes only a few hours.<br /><br />The discovery of PCR analysis in 1990 led to a major development in biological sciences, as PCR technology is used to diagnose diseases, clone genes, and the PCR test amplifies a specific part of DNA, as only small amounts of DNA are needed to produce sufficient copies for analysis, and the discoverer of the PCR test won the Nobel Prize in 1993.<br /><br />Using polymerase chain reaction analysis<br />PCR analysis is used to diagnose genetic diseases, or rapid diagnosis of infectious diseases and detect bacteria and viruses, identify pathogens, and perform acid fingerprinting Nuclear, and PCR analysis is also used in forensic medicine to identify criminals, or early diagnosis of some types of cancer.<br /><br />Polymerase chain reaction analysis steps<br />PCR analysis is performed by taking a small sample from the patient, a sample of liver or lung tissue may be taken, or a swab from the area between the nose and pharynx, or a blood sample may be drawn. It is worth noting that the sample depends on the type of genetic disease to be diagnosed, or the type of virus and bacteria and the area it infects.<br /><br />PCR testing technology relies on amplifying a part of the DNA in order to detect it, as the sample is first heated in order to separate the DNA into two strands of DNA, and a specific enzyme called Taq Polymerase builds each strand to be new DNA, meaning that the DNA is copied so that each molecule contains an old part of the DNA and a new part, and it is worth noting that it uses a thermal cycler, which is programmed to change the temperature to suit the analysis steps, and it takes a few hours to perform the PCR analysis and show the results.<br /><br />PCR technology is based on three main steps, and these steps are repeated thirty or forty cycles, as these steps are carried out on a thermal cycler that heats and cools the test tubes quickly, and each step of the PCR selection takes place at a different temperature, and the steps include the following:<br /><br />Replication: Replication or denaturation occurs at a temperature of 94 degrees Celsius, as the double-stranded DNA opens into two pieces of single-stranded DNA.<br /><br />Annealing: Annealing occurs at an average temperature of up to 54 degrees Celsius, where the polymerase enzyme begins to copy.<br /><br />Extension: Extension occurs at a temperature of 72 degrees Celsius, and the new DNA strand is paired with the original.<br /><br />Polymerase chain reaction (PCR) test results<br />The interpretation of PCR test results depends on the pathogen that the healthcare provider is trying to detect through the PCR test. PCR can only be used to determine the presence or absence of a known pathogen or gene. A positive result indicates the pathogen, and a negative result indicates the absence of the pathogen.<br /><br />Al-Mustaqbal University is the first university in Iraq