PCR tests, or Polymerase Chain Reaction tests, are laboratory techniques used to detect the presence of specific genetic material from organisms, such as viruses. They work by amplifying small amounts of DNA or RNA, making it easier to identify if a particular pathogen, like the SARS-CoV-2 virus responsible for COVID-19, is present in a sample. These tests are commonly used in medical diagnostics and research. A sample, often taken from a person's nose or throat, is processed in a machine that cycles through temperature changes to replicate the genetic material. This method is known for its accuracy and sensitivity, making it a reliable tool for detecting infections.