• Wash hands with warm water for at least 1–2 minutes or rub them together to improve blood flow.
• Stay well-hydrated by drinking plenty of water the day before and the day of collection to promote good circulation.
• Sit in a comfortable position with your hand below heart level to encourage blood flow.
• Take deep breaths and stay relaxed to avoid tensing up.

The ring finger or middle finger is generally recommended, as they provide good blood flow.

The number of spots required depends on the specific test, but generally, 3–5 well-sized spots are recommended.

• For Cytokines/CRP/HbA1c (duplicate testing): A minimum of two full, well-sized spots is required, with an additional spot recommended for potential retesting (total of three spots).
• For more than three biomarkers: It is recommended to fill all six spots on the DBS card to ensure sufficient sample volume for testing and any potential retests.
• Each spot should be fully filled for accurate analysis.

Saliva and DBS provide complementary biological information. Saliva is ideal for measuring many hormones and other analytes that change rapidly over time, while DBS offers access to blood-based biomarkers such as inflammatory markers, metabolic markers, and HbA1c.

Collecting both sample types allows researchers to gain a more comprehensive picture of physiology without requiring venipuncture.

The ideal sample type depends on your research question.

Saliva is commonly used for:

• Cortisol
• Melatonin
• Alpha-amylase
• Steroid hormones

DBS is commonly used for:

• CRP
• HbA1c
• Cytokines
• Lipids
• Other blood-based biomarkers

Our scientific team can help determine the most appropriate matrix for your analytes of interest.

Yes. Saliva and DBS are frequently collected during the same visit or collection session. Depending on your protocol, participants can provide a saliva sample followed by a simple fingerstick, adding only a few minutes to the overall collection process.

In most studies, we recommend collecting saliva before the DBS fingerstick.

Collecting saliva first helps avoid the possibility of blood contamination and is generally the simpler workflow for participants. If your saliva analytes are particularly sensitive to stress, maintaining a consistent collection order across all participants is recommended.

Yes. Both saliva and DBS are well suited for remote collection. Participants can collect both sample types using easy-to-follow instructions and return them to the laboratory for analysis.

This approach reduces participant burden while supporting decentralized and multi-site studies.

Not significantly. Most participants can complete both collections in a single session with minimal discomfort.

Adding a fingerstick to a saliva collection typically takes only a few additional minutes while substantially expanding the range of biomarkers available for analysis.

Potentially. Collecting complementary biomarkers from the same participant can provide richer datasets and allow researchers to address multiple study objectives from a single collection. Whether this reduces sample size depends on your study design and statistical analysis plan, but combining sample types often increases the amount of information gained from each participant.

• Lay the cards flat in a clean, dry area away from direct sunlight or heat for at least 4 hours or overnight.
• Avoid stacking cards to prevent contamination.

• After complete drying, store the DBS cards in a Ziploc bag with a desiccant to prevent moisture buildup, which can affect sample quality.
• The cards can be stored in the refrigerator for up to one week, but after a week, it is best to store them in a freezer -20c
• Maintaining cold chain management from post-drying through storage and shipping is important for preserving gold standard sample integrity

The cards can be bagged individually or be stored together (10 max per Ziploc bag with desiccant)

At this time, we do not recommend shipping DBS samples at room temperature.

• Use a Styrofoam container with an outer cardboard box and include frozen gel packs.
• An insulated mailer can be used to maintain the cold chain and protect sample integrity.

• No, all shipping documentation should list the contents as “Non-Infectious Exempt Human Specimens.”
• Label the external shipping container as “Exempt Human Specimens.”
• No additional shipping markings are required.

Yes, but export/import permits may be required depending on the destination country.

Yes. In many studies, saliva and DBS samples can be returned in the same shipment.

Shipping recommendations depend on the biomarkers being analyzed. Always follow the storage and shipping requirements for the most temperature-sensitive analyte to help maintain sample integrity.

Storage requirements depend on the biomarkers being measured.

DBS samples should be thoroughly dried before packaging with desiccant. Saliva storage recommendations vary by analyte. When collecting both sample types, follow the storage conditions required for the most sensitive biomarker in your study.

Touching the blood spots can contaminate the sample. If you accidentally touch a spot, try using a different one.

Ensure you are not squeezing your finger too hard, as this can affect sample quality. Also, be sure not to put blood on top of an already collected spot.

If the sample is improperly collected, it is best to repeat the collection on a different spot.

• The blood spot card should have large, fully filled circles.
• The spots should be evenly saturated without clots or smears.
• There should be no overlapping spots.

DBS samples are stable when stored at -20C for both short and long term storage. However, you can choose to store them with your saliva samples at -20C for short term storage and -80C for long term storage (over 6 months) if you want to keep samples together or storage temperatures consistent.

DBS samples remain highly stable when stored in the freezer. Research from Dr. McDade confidently supports stability for up to one year.

We recommend standard overnight at minimum for the highest sample quality.

Yes. Salimetrics offers customizable Participant Sampling Packs (PSPs) that can include both saliva and DBS collection supplies in a single kit, helping simplify participant collection and study logistics.

Yes. Salimetrics offers validated laboratory testing for both saliva and dried blood spot samples, allowing researchers to work with a single laboratory partner from sample collection through reporting.

Absolutely. Choosing the right sample type depends on your research objectives, target analytes, participant population, collection schedule, and storage considerations. Our scientific team can help you determine whether saliva, DBS, or a combination of both is the best fit for your study.