Due to mucins in saliva, and volume requirements for pipetting, we typically request more sample volume than is required for the testing. For example, cortisol tested in duplicate requires 50ul of saliva. However, we request at least 150ul saliva to better ensure we have enough sample volume to test as requested.
You can use the sample saliva sample to test many different analytes, and do not need to make aliquots of the samples for each analyte being tested from that sample.
Volume required for testing differs for each analyte, and whether samples are being testing in singlet, duplicate, or at a dilution.
It is best practice to freeze samples as quickly as possible after collection. This can reduce potential mold growth and analyte degradation in samples. A storage temperature of -20°C is sufficient for many analytes for a short period of time (days to weeks). However, for longer storage (>6 weeks), it is best to keep samples at -80°C until they are tested.
-20°C is the temperature of most home freezers, so if samples are collected in a home/work environment, they should be stored in the freezer as soon as possible and kept there until transferred to the study lab/clinic.
Some analytes are more sensitive to degradation than others (ex. cytokines), so it is important to store samples at -80°C as soon as possible.
IISBR offers archiving in one of our -80°C for a per sample fee. Please contact us for more information.
Upon arrival at IISBR, samples are assessed by laboratory staff as to whether they remained frozen during shipping. If thawing is observed or shipment is delayed,a note is made in the roster and all subsequent data files produced by IISBR. Samples are scanned in to an excel document using a barcode scanner, and verified against an investigator provided roster to ensure all samples IDs are correct prior to testing. Sample boxes are labeled with a barcode, and stored at -80C until tested.
On the day of testing, saliva is thawed at room temperature and mixed by vortexing for several seconds. Then saliva is spun at 3500 rpm in a centrifuge for 15 minutes, separating the supernatant from the mucins. The supernatant in each tube is used to test for the requested analytes.
We use a variety of kits from different manufacturers for our saliva and blood testing.
We typically use kits that have been validated by the manufacturer for use with the biospecimen type being used (saliva, blood, etc). However, if you want to use a kit not validated for use with your biospecimen type, we can test kits out to determine whether they can accurately measure the analyte in your specimen type.
Most of our kits come from Salimetrics, LLC (saliva), MesoScale Discovery (saliva or blood) or R&D (saliva or blood).
We typically guarantee data results within 4-6 weeks from the time samples arrive at IISBR.
However, this timeframe may be longer for studies with more samples or more analytes being tested for each sample.
If you are on a deadline, please let us know as soon as possible so we can expedite your testing. We do not charge extra for expedited requests.
We include the following information on the reports:
- Replicate concentration and mean concentration for all samples
- Qualitative Sample Information (ex. sample colors, viscosity, mucin content, possible blood contamination, suspected lipstick residue on tube, etc)
- Assay Detection Ranges
- Control Sample concentrations for each plate (we typically run 4 low and high control replicates on each singleplex plate, and 4 low, medium, and high control replicates on each multiplex plate)
- Inter-Assay CV %
- Assay Methodology
Our data reports are sent in the form of an excel document.
Immediately after testing, we store samples back in our -80°C freezers.
There are a few different options for how samples can be handled long term after all testing is complete: discarded by IISBR, archived at IISBR, or returned to the PI.
There are costs associated with each method. Please contact us for more information.
