Nucleic acid amplification test

A laboratory test that detects a target genetic sequence by making many copies of it or otherwise amplifying its signal. It is used to identify pathogens and other genetic targets.

Polymerase chain reaction: A method that repeatedly heats and cools a sample to copy selected DNA sequences using primers and a heat-stable polymerase. PCR is the best-known amplification chemistry used in these tests.
Nucleic acid: A DNA or RNA molecule that stores, transmits, or expresses genetic information. These tests measure DNA or RNA from a pathogen or other source.
COVID-19 testing: Testing methods used to identify current or past infection with SARS-CoV-2. NAATs, especially RT-PCR, became a central method for diagnosing COVID-19.
Antigen test: A diagnostic test that detects pathogen proteins or other antigens in a sample. Antigen tests detect pathogen components directly rather than amplifying genetic material.
False positive rate: The proportion of people without a condition who receive a positive test result. Contamination or nonspecific amplification can produce positive results that do not reflect infection.
Reverse transcription polymerase chain reaction: A method that converts RNA into complementary DNA before amplifying selected sequences by PCR. RNA viruses require a reverse-transcription step before conventional PCR amplification.
Primer (molecular biology): A short nucleic acid strand that provides a starting point for DNA synthesis. Primer sequences define which genetic region an amplification reaction copies.
Viral load: The amount of virus measured in a sample, commonly estimated from genetic material or infectious particles. Quantitative amplification assays can estimate pathogen burden, though results depend on assay design.
Serological test: A test that detects antibodies or antigens in blood or another bodily fluid. Serology often indicates an immune response, unlike NAAT detection of genetic material.
False negative rate: The proportion of people with a condition who receive a negative test result. Low target levels, poor sampling, or sequence changes can cause missed infections.

Linked from 13 pages