What is pooling testing for COVID-19?

Pooling—sometimes referred to as pool testing or pooled testing—means combining the same type of specimen from several people and conducting one NAAT laboratory test on the combined pool of specimens to detect SARS-CoV-2, the virus that causes COVID-19. Pooled tests that return positive results will require each specimen in the pool to be retested individually to determine which individual(s) are positive.

What is pooled sample testing?

See full answerPooling samples involves mixing several samples together in a “batch” or pooled sample, then testing the pooled sample with a diagnostic test. This approach increases the number of individuals that can be tested using the same amount of resources. For example, four samples may be tested together, using only the resources needed for a single test. However, because samples are diluted, which could result in less viral genetic material available to detect, there is a greater likelihood of false negative results, particularly if not properly validated. This method of pooling samples works well when there is a low prevalence of cases, meaning more negative results are expected than positive results.

What is pooled testing and how does it work?

Pooled testing could alleviate some of that problem. If a laboratory were to test a batch of 12 specimens, one of which was positive, it could then test smaller batches of four samples each. The smaller group with the positive sample would then be tested individually to identify the infected person.

What is the FDA’s policy on testing using pooled samples?

The FDA is aware that there is a great interest in performing testing using pooled samples. Pooling samples involves mixing several samples together in a “batch” or pooled sample, then testing the pooled sample with a diagnostic test. This approach increases the number of individuals that can be tested using the same amount of resources.

What happens if a pooled test result is negative?

If a pooled test result is negative then all the specimens can be presumed negative with the single test. In other words, all of the people who provided specimens can be assumed to test negative for SARS-CoV-2 infection and no additional testing is necessary.

What are the advantages of pooling test results?

Pooling allows laboratories to test more samples with fewer testing materials. It could be useful in scenarios like returning groups of workers to a workplace. What happens if the pooled test result is negative? If a pooled test result is negative, then all the samples can be presumed negative with the single test.