Types Stool Tests
There are two types of routine types stool tests: culture testing and PCR testing. Culture testing has been around for a long time and has been the gold standard for stool testing. PCR Testing is relatively newer (invented in 1983) and has become the new gold standard for stool testing. Each type of stool test is ordered by your doctor and completed by the patient.
You will receive a stool test kit, which after completed and analyzed produce stool test results on a stool test report. This report will tell the doctor what next steps to take in your treatment plan.
Culture testing is the most common form of stool testing available today.
What Does A Stool Culture Test For?
Culture testing looks at aerobic bacteria in the stool. This means that the specimen HAS TO be alive for the testing to work. Transport is very important in culture, as the specimen life is time-sensitive.
Culture testing requires about 1000-3000 cells for detection. A stool culture tests for bacteria and parasites in the stool to look for infections that may be causing patient symptoms.
Polymerase Chain Reaction (PCR) Testing
PCR testing is the testing of the 21st century. PCR testing is growing and is now the new gold standard of stool testing
What Does PCR Stool Testing Test For?
The PCR types stool tests looks at anaerobic bacteria, parasites, and viruses in the stool. This means that the specimen does NOT HAVE TO be alive for the testing to work. Transport is still important in this form of testing but it is not as time sensitive.
The PCR types stool tests requires about 1-3 cells for detection. PCR testing tests for bacteria, parasites, and viruses in the stool to look for infections that may be causing patient symptoms.
The PCR types stool tests also allows you to look for Gastrointestinal Inflammatory Markers (markers of inflammation in your GI tract) and Antibiotic Resistance (patient-specific resistances to antibiotics). The results from this type of testing is key in creating treatment options.
PCR vs. Culture
Culture testing is very time-sensitive. If the specimen does not reach the lab in 24-48 hours the results may be skewed or another sample may be needed. Culture deals with aerobic bacteria which die very quickly.
PCR testing is not as time-sensitive. The sample is recommended to go to the lab as soon as the test is completed, but allow a longer time (3-5 days) before results start to become skewed. PCR testing deals with anaerobic bacteria which means it can detect living and non-living (even after the specimen dies PCR testing can still detect bacteria, parasites, viruses).
Sensitivity & Specificity
Culture testing requires about 1000-3000 cells to detect most markers. When working with a small sample this can be harder to detect, skewing results and giving false negatives.
PCR Testing requires an equivalent of about 1-3 cells to detect most markers. When working with a small samples this can be very beneficial to detect, but results can be skewed and give false positives because of the ease in detection.
Culture testing stool sample results can take anywhere from 3-7 days because the bacteria needs to be grown for the labs to see the results.
PCR testing stool samples results can be done in 12-24 hrs because the bacteria does not need to be grown. Faster turnaround time leads to faster patient treatment
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