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 revolutionized the study of DNA and has been called one of the most important advances in molecular biology.
krisanapong detraphiphat / Getty Images
The small bits of DNA in a sample are usually inadequate for analysis.
Primers are created that match up with these DNA targets.
The sample to be tested is heated so double-stranded DNA produces single strands.
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.
Generally, it takes between 20 and 40 cycles to determine whether the target DNA is present.
If so, by that time there’s usually a sufficient sample for analysis, as well.
Identifying the genetic code of a pathogen doesn’t require the pathogen to be aliveunlike abacterial cultureor viral culture.
For medical facilities, these benefits mean faster, easier, less expensive tests.
The combined benefit of more testing and earlier detection of STIs is a major step forward.
They fare well on both measures of accuracy:
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?
Home test-kit results may offer further information about what to do if you did test positive for anything.
Your healthcare provider can help you decide when and how often you should be screened for STIs.
Muralidhar S.Molecular methods in the laboratory diagnosis of sexually transmitted infections.Indian J Sex Transm Dis AIDS.
2015;10(7):e0132776.
doi:10.1371/journal.pone.0132776
National Institutes of Health, National Institute of Allergy and Infectious Diseases.Sexually transmitted diseases.
2013 Aug;11(8):845-63. doi:10.1586/14787210.2013.814429.
