Saliva collection provides many advantages compared to other specimen collection options, such as urine collection. First, no professional training is needed for the specimen collection process. Second, it allows for remote sample collection by study participants, offering a high level of convenience. Some researchers have provided Mitra® devices to their study subjects for at home for self-collection of saliva samples.
Additional benefits of saliva sampling include:
The method is non-invasive and painless
It has a low risk of disease transmission
Saliva does not clot like other bio-fluids (i.e., blood)
Saliva samples can be stored for a longer time than other bio-fluids
Although research scientists say that a blood test provides more accurate results, a saliva test can be used to identify many substances and many biomarkers of disease. To provide the level of accuracy and specificity that research scientists require, saliva samples can be processed using more advanced equipment and special reagents.
Where is Saliva Sampling Applicable?
Saliva sampling is applicable in several research areas, as follows:
Infectious Disease Screening
When studying COVID-19 illness during the coronavirus pandemic, researchers realized that using saliva samples was a viable approach. The viral load is often higher in saliva than it is in other bio-fluids, such as in nasopharyngeal mucus.
During the Coronavirus Pandemic, researchers at Yale School of Public Health helped devise a new saliva test called ‘SalivaDirect,’ which aimed to simplify the collection and analysis processes while maximizing the efficiency of COVID-19 testing. With this test, a person spits into a sterilized container, which is sent to the lab for testing.
In the lab, the use of readily available enzymes instead of specialized and expensive reagents makes this saliva testing approach easier and more cost effective than conventional saliva testing. Lab techs also use PCR technology to quicken the process and further reduce costs. The group implementing SalivaDirect received Emergency Use Authorization (EUA) to use it during the COVID-19 crisis in advance of more formal approval.
Drug and Alcohol Screening
Saliva samples are useful in screening for alcohol, marijuana, cocaine, methamphetamine, and amphetamines. Saliva can provide accurate results, if the subject has used the substance recently. LabCorp reports that a drug can be detected in saliva less than an hour after last use and it remains detectable for up to 48 hours.
This timeframe can depend on the drug used, the dose, and the route of administration. Saliva sampling and testing are therefore helpful in traffic enforcement programs, where the primary concern is stopping people from driving soon after using a substance that impedes their ability to drive safely.
Saliva samples can be used to screen people for vitamin and hormone levels. Saliva samples provide accurate data for these tests, and also reflect any absorbed and bioavailable hormones. Sometimes, however, a blood test may also be necessary because saliva tests have high variability. With remote specimen collection kits that contain devices for sampling both saliva and blood specimens, people can be screened for hormone levels at different time points, as well as for a range of health conditions.
Many researchers use Neoteryx®Mitra® devices based on VAMS® technology from Trajan Scientific and Medical. These are portable, easy to use, and can be used to collect a small, precise amount of saliva, blood or other bio-fluid.