Nucleic Acid Testing (NAT)

This version of the course is no longer available.
Need multiple seats for your university or lab? Get a quote
The page below is a sample from the LabCE course . Access the complete course and earn ASCLS P.A.C.E.-approved continuing education credits by subscribing online.

Learn more about (online CE course)
Nucleic Acid Testing (NAT)

NAT is a gene-based method that can detect very small amounts of genetic material. It can detect HIV-1 earlier than antibody or antigen test methods. Because of the high-sensitivity of this method, NAT testing is used to screen donated blood, plasma, and tissue products. The FDA and AABB require both antibody and NAT testing.

A qualitative NAT method may also be the preferred method in the following situations:
  • When the anti-HIV screening test is negative and the patient is at increased risk for HIV infection
  • If the patient has participated in an HIV vaccine study and, as a result, may have developed antibodies to HIV
  • To diagnose infection in newborns born to HIV-positive mothers, as maternal antibodies would interfere with regular screening methods.
Quantitative NAT methods (also known as viral load assays) are used for patient monitoring after a diagnosis of HIV infection has been made.
The primary target of HIV NAT testing is viral RNA in plasma. An amplification step is employed, either target amplification or signal amplification, to increase levels of nucleic acids to detectable levels.