Table of ContentsView AllTable of ContentsHow It WorksPCR for STIsSTI Types and PCR
Table of ContentsView All
View All
Table of Contents
How It Works
PCR for STIs
STI Types and PCR
Polymerase chain reaction (PCR) analysis is a laboratory technique used to find small amounts ofDNA(genetic material) in a sample. Among other applications, PCR can be used to detect multiple sexually transmitted infections (STIs). For example, a lab can find DNA in aurine samplethat revealsgonorrheaorchlamydia.
PCR can be performed on DNA from many different types of samples, including:
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How Does PCR Work?
The small bits of DNA in a sample are usually inadequate for analysis. PCR allows scientists to make a bunch of copies of the material (calledamplification) quickly and inexpensively, which gives them enough to analyze.
In creating a PCR test, a target is selected, such as the DNA of different organisms that cause STI. Primers are created that match up with these DNA targets.
The sample to be tested is heated so double-stranded DNA produces single strands. The primers can then attach to any target DNA in the sample (such as from an STI-producing organism).
After this, a DNApolymerase(enzyme) is added and starts replicating the DNA where it meets up with the primer. This creates many copies of that target stretch of DNA, a process called amplification.
This cycle is repeated. With each cycle, the amount of the target DNA segment increases exponentially. In the first cycle, one copy becomes two. Then two copies become four, then become eight, etc.
Why PCR Is Relevant to STI Testing
Polymerase chain reaction, and related techniques likeligase chain reaction, are growing in importance for STI testing.That’s because these techniques can directly identify small amounts of viral DNA or RNA in samples.
Identifying the genetic code of a pathogen doesn’t require the pathogen to be alive—unlike abacterial cultureor viral culture. It also means the infection can be recent enough that the body hasn’t yet developed detectable antibodies for it, which gives it an advantage over a type of testing called ELISA.
Benefits of PCR
This means PCR techniques can sometimes detect sexually transmitted infections (and other diseases) earlier than other tests. Even better, samples don’t need to be taken at exactly the right time, and they’re easier to handle because you don’t have to worry about keeping pathogens alive.
For medical facilities, these benefits mean faster, easier, less expensive tests. Tests are now available that can identify at least nine different STI-related pathogens at once, which makes them less labor-intensive, as well.
Home Testing
These benefits also have made home testing kits for STIs much more accurate and reliable.That’s especially important for this kind of infection because a lot of people are embarrassed to go to their healthcare provider for testing, and home testing can often be done sooner than someone could get into see a healthcare provider, as well.
The combined benefit of more testing and earlier detection of STIs is a major step forward. Not only can prompt treatment help toprevent many complications,rapid identification means you can take immediate steps to keep from spreading it.
How Home Testing WorksWith home testing kits, you collect your own sample with the provided supplies, send it in to the lab, and receive results directly.
How Home Testing Works
With home testing kits, you collect your own sample with the provided supplies, send it in to the lab, and receive results directly.
The Best At-Home STI Tests
Medical facilities use PCR to detect a large number of pathogens related to sexually transmitted infections.
Bacterial STIs
Viral STIs
Parasitic STI
Frequently Asked Questions
How accurate are PCR test results?
What is multiplex PCR testing?
Multiplex PCR testing is when one test looks for multiple infectious agents simultaneously. Examples are STI PCR tests that look for up to nine pathogens.
What information is included in a PCR STI panel?
The results you get after a PCR STI panel, whether from a healthcare provider or self-test kit, should include information about:
They may also have numbers representing the severity of an infection. Home test-kit results may offer further information about what to do if you did test positive for anything.
A Word From Verywell
STI testing is an important part of protecting your health, that of your partner(s), and possibly that of your future children.Just about everyoneshould get checked for STIs once, and depending on your age, overall health, and sexual practices, you may benefit from getting checked routinely.
Your healthcare provider can help you decide when and how often you should be screened for STIs. If you’re not comfortable talking about it with your regular healthcare provider, you can go to a local clinic or look into home testing. However, remember that if you do have a positive test, you’ll need to go to a healthcare provider for treatment.
Safe Sex: How to Avoid STIs
5 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Muralidhar S.Molecular methods in the laboratory diagnosis of sexually transmitted infections.Indian J Sex Transm Dis AIDS. 2015;36(1):9-17. doi:10.4103/0253-7184.156686National Institutes of Health, National Human Genome Research Institute.Polymerase chain reaction (PCR) fact sheet.Kriesel JD, Bhatia AS, Barrus C, Vaughn M, Gardner J, Crisp RJ.Multiplex PCR testing for nine different sexually transmitted infections.Int J STD AIDS. 2016;27(14):1275-1282. doi:10.1177/0956462415615775Lunny C, Taylor D, Hoang L, et al.Self-collected versus clinician-collected sampling for chlamydia and gonorrhea screening: a systemic review and meta-analysis.PLoS One. 2015;10(7):e0132776. doi:10.1371/journal.pone.0132776National Institutes of Health, National Institute of Allergy and Infectious Diseases.Sexually transmitted diseases.Additional ReadingBarrientos-Durán A, de Salazar A, Alvarez-Estévez M, Fuentes-López A, Espadafor B, Garcia F.Detection of sexually transmitted disease-causing pathogens from direct clinical specimens with the multiplex PCR-based STD Direct Flow Chip Kit.Eur J Clin Microbiol Infect Dis. 2020;39(2):235-241. doi:10.1007/s10096-019-03686-wMunson E, Napierala M, Schell RF.Insights into trichomoniasis as a result of highly sensitive molecular diagnostics screening in a high-prevalence sexually transmitted infection community.Expert Rev Anti Infect Ther. 2013 Aug;11(8):845-63. doi:10.1586/14787210.2013.814429.
5 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Muralidhar S.Molecular methods in the laboratory diagnosis of sexually transmitted infections.Indian J Sex Transm Dis AIDS. 2015;36(1):9-17. doi:10.4103/0253-7184.156686National Institutes of Health, National Human Genome Research Institute.Polymerase chain reaction (PCR) fact sheet.Kriesel JD, Bhatia AS, Barrus C, Vaughn M, Gardner J, Crisp RJ.Multiplex PCR testing for nine different sexually transmitted infections.Int J STD AIDS. 2016;27(14):1275-1282. doi:10.1177/0956462415615775Lunny C, Taylor D, Hoang L, et al.Self-collected versus clinician-collected sampling for chlamydia and gonorrhea screening: a systemic review and meta-analysis.PLoS One. 2015;10(7):e0132776. doi:10.1371/journal.pone.0132776National Institutes of Health, National Institute of Allergy and Infectious Diseases.Sexually transmitted diseases.Additional ReadingBarrientos-Durán A, de Salazar A, Alvarez-Estévez M, Fuentes-López A, Espadafor B, Garcia F.Detection of sexually transmitted disease-causing pathogens from direct clinical specimens with the multiplex PCR-based STD Direct Flow Chip Kit.Eur J Clin Microbiol Infect Dis. 2020;39(2):235-241. doi:10.1007/s10096-019-03686-wMunson E, Napierala M, Schell RF.Insights into trichomoniasis as a result of highly sensitive molecular diagnostics screening in a high-prevalence sexually transmitted infection community.Expert Rev Anti Infect Ther. 2013 Aug;11(8):845-63. doi:10.1586/14787210.2013.814429.
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Muralidhar S.Molecular methods in the laboratory diagnosis of sexually transmitted infections.Indian J Sex Transm Dis AIDS. 2015;36(1):9-17. doi:10.4103/0253-7184.156686National Institutes of Health, National Human Genome Research Institute.Polymerase chain reaction (PCR) fact sheet.Kriesel JD, Bhatia AS, Barrus C, Vaughn M, Gardner J, Crisp RJ.Multiplex PCR testing for nine different sexually transmitted infections.Int J STD AIDS. 2016;27(14):1275-1282. doi:10.1177/0956462415615775Lunny C, Taylor D, Hoang L, et al.Self-collected versus clinician-collected sampling for chlamydia and gonorrhea screening: a systemic review and meta-analysis.PLoS One. 2015;10(7):e0132776. doi:10.1371/journal.pone.0132776National Institutes of Health, National Institute of Allergy and Infectious Diseases.Sexually transmitted diseases.
Muralidhar S.Molecular methods in the laboratory diagnosis of sexually transmitted infections.Indian J Sex Transm Dis AIDS. 2015;36(1):9-17. doi:10.4103/0253-7184.156686
National Institutes of Health, National Human Genome Research Institute.Polymerase chain reaction (PCR) fact sheet.
Kriesel JD, Bhatia AS, Barrus C, Vaughn M, Gardner J, Crisp RJ.Multiplex PCR testing for nine different sexually transmitted infections.Int J STD AIDS. 2016;27(14):1275-1282. doi:10.1177/0956462415615775
Lunny C, Taylor D, Hoang L, et al.Self-collected versus clinician-collected sampling for chlamydia and gonorrhea screening: a systemic review and meta-analysis.PLoS One. 2015;10(7):e0132776. doi:10.1371/journal.pone.0132776
National Institutes of Health, National Institute of Allergy and Infectious Diseases.Sexually transmitted diseases.
Barrientos-Durán A, de Salazar A, Alvarez-Estévez M, Fuentes-López A, Espadafor B, Garcia F.Detection of sexually transmitted disease-causing pathogens from direct clinical specimens with the multiplex PCR-based STD Direct Flow Chip Kit.Eur J Clin Microbiol Infect Dis. 2020;39(2):235-241. doi:10.1007/s10096-019-03686-wMunson E, Napierala M, Schell RF.Insights into trichomoniasis as a result of highly sensitive molecular diagnostics screening in a high-prevalence sexually transmitted infection community.Expert Rev Anti Infect Ther. 2013 Aug;11(8):845-63. doi:10.1586/14787210.2013.814429.
Barrientos-Durán A, de Salazar A, Alvarez-Estévez M, Fuentes-López A, Espadafor B, Garcia F.Detection of sexually transmitted disease-causing pathogens from direct clinical specimens with the multiplex PCR-based STD Direct Flow Chip Kit.Eur J Clin Microbiol Infect Dis. 2020;39(2):235-241. doi:10.1007/s10096-019-03686-w
Munson E, Napierala M, Schell RF.Insights into trichomoniasis as a result of highly sensitive molecular diagnostics screening in a high-prevalence sexually transmitted infection community.Expert Rev Anti Infect Ther. 2013 Aug;11(8):845-63. doi:10.1586/14787210.2013.814429.
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