Steroid hormones and other biomarkers can be detected in different bodily fluids. Although serum is preferred by many, it is also possible to analyze whole-blood, urine and saliva. Each test substance has its own merits and often the questioning and the biomarkers dictate which substance is to be analyzed. It is important not to forget that comparability is not given if the results were obtained by different methods.
The biggest advantage in testing saliva samples is, in contrast to blood, only unbound hormones are measured. In blood samples, most lipophile steroid hormones are bound to transport proteins, which render them inactive and unavailable for cells. But in saliva only unbound, biologically active, hormones are found, which correlate directly with current hormone activity.
Many hormones and biomarkers are subject to fluctuation, depending for example on the circadian rhythm (i.e. cortisol) or the menstrual cycle (i.e. estradiol, progesterone, and testosterone). Because of that repeatet sample collection is imperative. For its simplicity and flexibility saliva testing is the best option to compile circadian and cyclic hormone profiles. At home, at work, or on the go saliva samples can be collected sanitarily and fast, staying stable for 3 to 4 days at room temperature.
1. Sample collection – quick and convenient
There are different ways to collect the required amount of saliva. It can be collected with a straw-like device into a small plastic tube, or through softly chewing a synthetic fiber roll (Salivette®) for a minute.
Additionally, there are systems designed to be used specifically for young children and infants, which are also used for collecting saliva samples of animals.
2. Shipment – easy and uncomplicated
The shipment of collected samples to our lab can be done without much effort, since saliva samples remain stable at room temperature for several days. Nevertheless samples should be shipped promptly and packed in a professional manner. If they are to be stored for a prolonged period of time they should be frozen at -20°C to prevent bacterial growth. Please contact our lab (+49 (0)651 9120 494 or salivalab(at)daacro.de) before you ship to tell us your shipments tracking number, if possible.
We suggest shipping from Monday to Wednesday, so that the samples arrive at our lab before the weekend. If the amount of samples is high please send us an Excel-chart including sample numbers and the time at which the sample was collected. Already frozen samples should always be shipped with dry ice.
For international shipment please make sure that the “Declaration of biological shipments” has to be completed and placed on the package in clear sight.
daacro GmbH & Co. KG
Saliva Lab Trier
3. Analysis – fast and reliable
After analyzing the samples we relay the results to you in an Excel-sheet. If we investigated the Corstisol Awakening Response (CAR) an extensive report will be provided for you. Please note that we store all saliva samples at -20°C for two months after analysis.
After that the samples are disposed of; further storage, or sending back of samples is possible (for added expense).
4. Quality assurance – accurate and validated
Saliva samples are analyzed in a 96er well-plate, double if requested. For quality control the CV can be calculated from two individual values: CV (Coefficient of Variation) = standard deviation of two individual analyses / mean of two individual analyses. The permitted deviation depends on the present cortisol-concentration: for cortisol measures of more than 2 nmol/L the CV should be below 15%, for lesser concentration more deviation is permitted.
The average of the individual CVs is reported as the so called intra-assay-CV. Additionally on each plate internal controls of their own known concentration are measured to calculate the inter-assay-CV. Researchers in the social and behavioral sciences typically report these two values in their publications to express the precision, or repeatability, of immunoassay test results.
Our lab works in accordance with international standards and GCP / GLP guidelines. Our strict quality assurance provides SOPs for all laboratory related processes. This includes assay kit storage (refrigerator at 2-8°C) and sample storage (freezer-20° C or -80° C) with a temperature control system. The analyses are carried out according to the specifications of the manufacturer and taking into account existing work instructions and SOPs. The High Sensitivity Salivary Cortisol Enzyme Immunoassay of Salimetrics is FDA 510k assigned (no. K011323 / K031348).
All our technical supply is maintained in accordance with manufacturer’s specifications and receives monthly/annual upkeep by a technician. These quality standards plus our internationally well acknowledged scientific expertise in the field of psychoneuroendocrinology qualified us a Center of Excellence for Salimetrics assays.
These quality standards plus our internationally well acknowledged scientific expertise in the field of psychoneuroendocrinology qualified us a Center of Excellence for Salimetrics assays. More information can be found here: www.salimetrics.com/labs.