Saliva Collection

Two sampling methods are used to collect saliva: sampling using absorbent oral swabs, and sampling by passive drool, in which saliva is allowed to pool in the mouth, and gently forced through a sampling tube into a collection vial.

The passive drool method is seen as the “gold standard” for sampling as it allows visual measurement of the volume collected, and as a sampling method it does not interfere with any of the Salimetrics assays. Conversely, cotton-based swabs have been shown to interfere with the measurement of several analytes, leading to inaccurate results. The SalivaBio swabs supplied by Salimetrics are made using a proprietary polymer which does not cause the same problems as cotton, and have been validated for use with many assays. They are therefore a superior method to use for many analytes, but are unfortunately still not suitable for use with all analytes. For a table of analytes that have been validated for collection with SalivaBio oral swabs when tested with Salimetrics Salivary Assay Kits, please contact us, or follow this link.

Automated Testing

Automated testing at Anglia Ruskin Biomarker Analysis Laboratory requires a greater volume of saliva than ‘manual’ testing using normal multichannel pipettes. The volumes given in the assay kit manual for your analyte will NOT be sufficient for automated testing. Longer sampling times for swab collection are also strongly advised when performing automated testing –see below for details – and if you are new to swab collection, we recommend you try some pilot collections to check the volume obtained before you start sampling for your project.

Low sample volume?

Anglia Ruskin Biomarker Analysis Laboratory can perform manual testing.  If you have samples that are expected to be low-volume (e.g. from dogs, neonates, or participants who are expected to have xerostomia (dry-mouth)) please inform us when you ask for your quote.

Need help with collection methods?

Comparison of Collection Methods



Assay Interference


Monitoring collected volume



Mouth location



Intended Usage



Sample quality




Flow rate effects



Participant burden






Passive drool

Does not interfere with ELISA-based assays if using suitable collection devices

The volume of collected saliva can easily be visually confirmed – ideal for flow-rate measurement

Differences in analyte concentration at different mouth locations are not a consideration for passive drool, but you cannot use it to collect from specific mouth locations.

Cannot be used in animals or infants, difficult to use in children <6

Sample is more viscous with more particulate, making handling more difficult & potentially giving higher %CVs in testing. A greater volume is needed for accurate pipetting.

Passive flow – sampling can take longer, putting more burden on participants. It is much easier to measure flow rate using passive drool.  

Can be seen as unpleasant by participants. The SalivaBio Saliva Collection Aid (SCA) has been designed to partially overcome this issue and increase compliance.

Cryovials can be conveniently stored at -20°C/ -80°C without volume loss by evaporation.

Salimetrics Oral Swabs

Can interfere with ELISA-based assays for certain analytes. (Contact us)

The volume of saliva collected can only be confirmed accurately by weighing before and after sampling.

Mouth location must be specified & controlled for swab collection, but you can also use swabs to collect from specific mouth locations.

SalivaBio Infant Swabs (SCS) and SalivaBio Childrens’ Swabs can be used by researchers to collect saliva from infants and children. SCS are popular to use when collecting from animals

Sample is less viscous with less particulate, giving easier handling of lower volumes & potentially lower %CVs in testing.

Stimulated flow – Sampling takes less time, but when measuring flow rate you must be careful not to fully saturate swabs, and can only monitor collected volume by weight.
More convenient, lower burden.

More convenient, lower burden.

Swab storage tubes must be sealed with parafilm and stored in an air-tight container if stored for longer than 3 months at -20°C/ -80°C