Measurement error of salivary cortisol in established-qualified labs is minimal.
(PRWEB) October 19, 2017
A new study published in BioMed Central Research Notes shows that using an established-qualified lab provides the best opportunity for consistent, reproducible data. Dr. Calvi and collaborators explored the possibility that inconsistent findings due to variations in assay performance from different laboratories may contribute to unsystematic error in salivary measurements, specifically for salivary cortisol. To test this, researchers sent aliquots of 100 saliva samples to 9 different academic labs that routinely measure salivary cortisol to determine the variability between labs and the reproducibility of salivary cortisol measurements. The results identified only 1.76% of the variation in actual salivary cortisol values could be attributed to differences in the cortisol assay from Salimetrics, a key indicator for high-quality salivary assays, and only 7.93% of measurement variation was due to differences between labs. The study concluded that “measurement error of salivary cortisol in established-qualified labs is minimal.”
“This is an important study, because it confirms that the measurement of salivary cortisol using the Salimetrics assay in a qualified lab is reproducible and valid,” says Steve Granger, Ph.D., Salimetrics CSO. “A key finding is that the results show a mere 0.11% variance between standards and controls, which demonstrates an industry-leading level of consistency across the assays performed. For researchers, this study provides confidence in the power of the data generated by Salimetrics' salivary assay kits when run properly in a qualified lab.”
The study identified criteria for a qualified-established lab as: (1) following and enforcing standard procedures; (2) uniform training for laboratory personnel; (3) proper calibration, preventative care and maintenance of laboratory equipment; (4) adhering to a scientifically credible repeat criterion; (5) being able to provide evidence of reproducibility; and (6) maintaining high standards for CVs. Salimetrics has always recommended using a lab that meets these criteria. In addition, Salimetrics recommends that a lab also actively participate in proficiency testing, perform and document maintenance and calibration on lab equipment, and be highly experienced in analyzing saliva samples for specific analyte(s) of interest.
Qualified labs understand that saliva is a heterogeneous sample matrix, and sample processing largely contributes to the ability of a saliva testing laboratory to generate quality results, as found in this study. Experienced technicians are better equipped to handle inter-individual sample differences such as viscosity, turbidity, and particulate matter. “Salimetrics assay kits are designed to maximize accuracy and precision to account for saliva matrix effects and the lower concentrations of analytes typically found in saliva. In the hands of an experienced lab, the technicians will be better equipped to handle the intricacies associated with saliva handling, and will know how to maintain sample integrity to minimize variation in sample concentrations,” says Dr. Granger.
Salimetrics SalivaLab is the largest established and qualified saliva lab in the world today. It is dedicated to helping researchers throughout the study process. “It’s important for researchers to compare their resources carefully, and allocate resources and budget to get the best data,” says Hans Schroeder, Salimetrics CEO. “Beyond accuracy, Salimetrics works with researchers to reduce the burden of collecting and handling samples from start to finish.”
Researchers can visit the Salimetrics SalivaLab webpage to learn more about what makes qualified labs like the Salimetrics SalivaLab the best choice for a successful salivary bioscience study.
Salimetrics’ assay kits and CLIA-certified testing services are used to measure salivary analytes related to stress, behavior and development, inflammation, sleep, reproduction, health and immune function. Founded in 1998 by Douglas A. Granger, Ph.D., Salimetrics, LLC supports CROs, pharmaceuticals, academic researchers and the immunodiagnostic industry around the world with innovative immunoassay products, non-invasive saliva collection methods, and laboratory testing services.