Understanding How PCR Is Used in Medicine

PCR stands for polymerase chain reactions, an instrumental method that copies a DNA sample to amplify a small amount of DNA to study it more thoroughly on a larger scale. PCR has dramatically transformed the landscape of scientific research and diagnostic medicine. PCR molecular methods have revolutionized the detection and characterization of microorganisms in a broad range of medical diagnostic fields. These fields include virology, mycology, parasitology, microbiology, and dentistry. Read on for a greater understanding of how PCR is used in medicine today.


In virology, PCR helps detect and characterize the nucleic acids of viruses, enabling comprehensive viral characterization and a greater understanding of the virus’s behavior during infection within a host. This understanding has greatly aided clinical treatment and the advancement of research for specific viruses.

Examples of Virology and PCR

COVID-19 diagnosis is one of the many viral uses of PCR. Real-time PCR (RT-PCR) is a highly sensitive and rapid PCR technique that can deliver diagnosis results in just a few hours, a vital aspect of managing the COVID-19 spread.

To detect COVID-19 in patients using RT-PCR, a sample is collected. This sample typically comes from the person’s nose or throat. Then, the RNA from the sample is extracted; this will also include the virus’s RNA if it is present in the host. The RNA is then reverse transcribed into DNA, and researchers add additional fragments of complementary DNA to the viral DNA. If the virus is present, these fragments will attach to the target sections of DNA. Some of these genetic fragments will then add marker labels to the strands to detect the virus as well.

Next, the DNA mixture goes through the PCR process, including denaturation, or separating the strands, annealing, where primers attach to the sequence and elongation, where a polymerase enzyme adds nucleotides to the ends of the primers to create two double-stranded DNA molecules.

However, in the RT-PCR process, unlike the conventional PCR method, fluorescence is added to the new sections of the DNA. A certain level of fluorescence present will determine if the COVID-19 virus is present.

Mycology and Parasitology

PCR technology has also become fundamental in mycology and parasitology by enabling early identification of the microorganisms, thus aiding efficient diagnosis and treatment of infections. The technique is fast and highly specific and can be used to detect trace amounts of fungal DNA from environment samples before symptoms occur. Therefore, it allows for the implementation of early disease control methods.

Examples of PCR and Mycology and Parasitology

A common use of PCR in mycology is through detecting infections from Aspergillus ssp. in patients with neutropenia. This disease is notoriously difficult to diagnose due to the low sensitivity of the culture method and the difficulty of finding histopathological specimens in individuals with low platelet counts. However, early treatment is essential to achieving the best results. PCR can reduce the time required for the diagnosis. RT-PCR has successfully quantified the number of pathogens, therefore assisting in decisions regarding how to treat fungal diseases and assess the effects of fungi.

PCR methods also assist in parasitological diagnostics as well. Many parasites are not cultivable in the laboratory. Microscopy supports malaria diagnosis, but PCR can diagnose this illness even in difficult situations due to its greater sensitivity.


PCR is a highly valuable technique in microbiology as it allows crucial observations for microorganism detection with the aid of product development solutions for life sciences. Conventional PCR has been used for more than a decade in clinical microbiology research to identify microbial pathogens. However, this technique has been restricted to detecting microorganisms that either have slow growth or cannot be cultivated. Most tests with conventional PCR involve multiple steps and require careful expertise. Real-time PCR has important, immediate implications for diagnostic tests in the clinical microbiology laboratory. Due to the enhanced sensitivity, ease of use, and quickness of this technology, it has become an attractive alternative for detecting microorganisms in humans in comparison to conventional PCR.

Examples of PCR and Microbiology

Anaerobic bacteria are present in a broad range of infections commonly associated with considerable morbidity and mortality rates. Although different types of these bacteria are often in diverse infections, many of these clinically significant pathogens are poorly characterized due to the inadequacy of conventional anaerobic bacteriological and phenotype tests.

Luckily, molecular detection methods are a powerful means of identifying these pathogens in the study of the parasite-host relationship, clarifying the taxonomic positions of known pathogens. Therefore, there is a growing trust in genotyping for microbial characterization. Genotypes are more specific, more easily quantified, and more standardized between different organisms than traditional phenotype markers. PCR technology is one of the most significant advancements in molecular bacterial diagnostics. Real-time PCR has been used in the detection and quantification of anaerobic bacteria. This discovery provides users with the ability to amplify DNA and detect and confirm the specific sequences of microorganisms.


The PCR technique has become a standard diagnostic and research tool in the field of dentistry. PCR and other molecular biology techniques enable the diagnosis of infectious microbes that cause maxillofacial infections. This helps effectively manage conditions such as periodontal disease, caries, oral cancer, and endodontic infections.

Examples of PCR and Dentistry

One of the uses of PCR in dentistry is the detection of markers in the diagnosis and prognosis of some oral cancers. Diagnoses, prognoses, and treatment can all improve through the study and use of genetic markers identified through PCR and other molecular biology procedures.

Squamous cell carcinoma of the oral cavity is generally accompanied by other types of aerodigestive tract carcinomas, such as oropharyngeal and esophageal carcinoma. Streptococcus anginous is a bacterium that may isolate in different parts of the body and has been isolated in squamous cell carcinoma in the head and neck. Through real-time PCR, detection of streptococcus anginous occurs with greater sensitivity and specific approximation in the oral cavity’s squamous cell carcinomas.

There is a lot that goes into understanding how PCR is used in medicine. Some of the largest subsection of medicine that the technology has made great strides in includes diagnosis and research within virology, mycology and parasitology, microbiology, and dentistry.

Understanding How PCR Is Used in Medicine