A Comprehensive Overview of Saliva Collection Sticks
What are saliva collection sticks and how are they used?
Saliva collection sticks are devices used to obtain saliva samples for diagnostic testing. They consist of an absorbent material, like cotton or synthetic fibers, attached to a handle. The absorbent tip is placed in the mouth to collect saliva by absorption. The saliva can then be recovered for analysis by centrifuging or compressing the stick. Saliva collection sticks provide a simple, non-invasive way to collect saliva samples.
What factors affect salivary cortisol analysis when using saliva collection sticks?
A key consideration when using saliva collection sticks for cortisol analysis is the material of the stick. A 2006 study by Mörelius et al. found that wooden stick saliva collection sticks can artificially lower cortisol levels if the saliva is not centrifuged immediately after collection. They found salivary cortisol levels dropped significantly when saliva collected on wooden sticks was centrifuged 24 hours or 48 hours after collection, compared to being centrifuged immediately. However, cortisol levels were consistent regardless of centrifugation time when plastic stick collection devices were used. The authors concluded wooden stick saliva collection devices should not be used for cortisol analysis unless centrifugation can occur right away. The findings indicate the stick material can impact cortisol measurement and introducing different stick materials within one study is not advisable.
How do different saliva collection methods compare for protein analysis?
Michishige et al. (2006) compared saliva collection by suction, spitting into a dish, and use of cotton Salivette sticks for total protein, IgA, kallikrein, and protease analysis. Total protein, IgA, trypsin-like activity, and protease levels were higher in Salivette samples compared to suction or spitting. However, the large standard deviations make the results unclear. Topkas et al. (2012) found no difference in total protein levels between passive drool, SOS swabs, Salivette cotton and synthetic swabs, and liquid-based collection. But significant differences were observed between methods for CRP, IgE, and myoglobin. The findings indicate total protein can be measured consistently across collection methods, but levels of specific proteins may vary. This highlights the need to validate collection techniques for particular proteins of interest.
What is the comparative performance of different collection sticks for steroid hormone analysis?
Gröschl et al. (2006) tested cotton, synthetic, and foam tipped swabs for steroid analysis. Synthetic swabs performed best, with near complete recovery and reproducible volumes. Cotton swabs performed poorly, with low, variable recovery. Foam-tipped swabs also had very low analyte recovery. Gröschl et al. (2008) further found Salivette synthetic and polyethylene swabs performed well for steroid analysis, as did the Quantisal device. Cotton swabs and the SCS liquid system performed poorly. The findings indicate synthetic swabs are optimal for steroid collection, while other materials may interfere.
How suitable are saliva collection sticks for sampling from infants or fragile individuals?
Saliva collection sticks provide a simple way to collect saliva from infants or individuals unable to actively spit or drool. Hodgson & Granger (2013) used cotton sticks to successfully collect sufficient saliva for cortisol analysis from infants and the elderly. Holm-Hansen et al. (2004) compared fluid absorption and release between 8 different swab-type collection devices. All swabs performed similarly in uptake and release of water and saliva. But differences in sampled volumes were observed, with Salivette collecting 4 times more than others. Swab-based collection is simple enough for fragile individuals, though differences in collection capacity between sticks exist.
What is the impact of collection sticks on downstream molecular testing?
Krone et al. (2016) found DNA from saliva dried onto filter paper cards was stable for up to 35 days and concentrations matched fresh saliva samples. This indicates collection sticks allowing saliva to dry could enable room temperature transport for molecular testing. However, Takagi et al. (2013) found significantly lower protein levels were recovered from Salivette swabs compared to direct drool, suggesting an impact on molecular assays. More research is needed, but collection sticks may impact molecular outcomes depending on material interactions and drying.
Can saliva collection sticks enable at-home self-collection?
Yes, the non-invasive, simple nature of saliva collection sticks allows them to be used for at-home self-collection. Orasure's Intercept device uses an absorbent pad on a stick for supervised drug testing. Norgen Biotek also uses saliva collection sticks coupled with preservative vials to enable self-collection for genetic testing. And Copan's LolliSponge uses a lemon-flavored swab stick to stimulate saliva production for self-collection. The ease and safety of these collection sticks makes them a viable option for unsupervised saliva collection by patients themselves.
How does stick design impact collection volume and convenience?
Collection capacity is an important stick design consideration, as absorbent material, surface area, and geometry impact volume. Holm-Hansen et al. (2004) found larger swab size correlated with higher capacity, with Salivette collecting far more than alternatives. The LolliSponge has an elongated triangular shape allowing saliva absorption along both sides, while Intercept utilizes a larger foam pad to maximize volume. Collection volume also impacts duration - a larger capacity reduces collection time which improves convenience for the user. However, overly large designs could impede comfortable placement and retention in the mouth.
Can collection sticks allow point-of-care saliva testing?
Yes, the clean, dry nature of saliva collection sticks allows them to be directly integrated with point-of-care test devices. Branan Oratect device uses an absorbent pad connected to a test unit for drugs of abuse detection. Medico swabs offer Saliva Collection Kits which combine swabs with buffers and tubes compatible with centrifuges and molecular testing equipment. The simplicity of collection sticks makes them ideal for point-of-care applications as they don't require any preprocessing before testing.
In summary, saliva collection sticks provide a fast, non-invasive approach to gather saliva samples for analysis. However, factors such as material, geometry, and downstream testing impact their performance and must be taken into account. Overall, these devices allow simple, untrained saliva collection in a variety of settings. Continued research and standardization is needed to ensure reliable, high quality results.
Click to View → Mantacc Saliva Collection Sticks / Mantacc 93054 Saliva Collection Stick
1. Mörelius E, Nelson N, Theodorsson E. Saliva collection using cotton buds with wooden sticks: a note of caution. Scand J Clin Lab Invest. 2006;66(1):15-8. doi: 10.1080/00365510500402166. PMID: 16464783.
2. E. Mörelius, N. Nelson & E. Theodorsson (2006) Saliva collection using cotton buds with wooden sticks: A note of caution, Scandinavian Journal of Clinical and Laboratory Investigation, 66:1, 15-18, DOI: 10.1080/00365510500402166
3. Francesca G. Bellagambi, Tommaso Lomonaco, Pietro Salvo, Federico Vivaldi, Marie Hangouët, Silvia Ghimenti, Denise Biagini, Fabio Di Francesco, Roger Fuoco, Abdelhamid Errachid, Saliva sampling: Methods and devices. An overview, TrAC Trends in Analytical Chemistry, Volume 124,
2020, 115781, ISSN 0165-9936, https://doi.org/10.1016/j.trac.2019.115781.