What is DBS?
Dried blood spot testing (DBS) is a form of biosampling where blood samples are blotted and dried on filter paper. The dried samples can easily be shipped to an analytical laboratory and analysed using various methods such as DNA amplification or HPLC.
In the lab, a 3mm sample is cut. With a single drop two to four parameters (HIV, Syphilis, Hepatitis, Cholesterol, Glucose, etc.) can be analyzed, using an appropriate solvent which extracts the biological material that is required for the test. This room-temperature extraction (stove & shaker) occurs inside a micro plate and read-out is done on an ELISA’s reader.
How To Collect DBS?
Dried blood spot specimens are collected by applying a few drops of blood, drawn by lancet from the finger or toe, onto specially manufactured absorbent filter paper. The blood is allowed to thoroughly saturate the paper. Choose finger for sampling (2nd or 3rd index finger recommended).
Stimulate blood flow by shaking hand briefly or massage finger from
hand to fingertip a few times.
Clean finger with isopropyl alcohol and allow to dry completely.
Perform stick with incision device and gently wipe off first drop of blood using a sterile dry gauze or cotton ball.
Allow formation of a large drop of blood.
Lightly touch the blood drop to one side of the filter paper allowing blood to fill the preprinted circle completely.
Do not touch the DBS card directly to the finger stick site!
Repeat until all circles are filled (which circles is required).
How To Dry DBS?
Allow the specimen to dry at room temperature.
Dry the cards horizontally and not touching each other for a minimum of 3 hours.
Do not touching or smearing the blood spots.
Do not expose the card to heat, moisture or direct sunlight.
Once dried, the sample can be transported by any means to the lab – NO need for cold chain or any special conditions. See regulations.
How to Package DBS
It is important to package each DBS card separately so that the cards do not contaminate each other.
Package each DBS separately.
Insert into sealable plastic bag or envelope and add desiccant packs.
Fill in the requested information on the envelope or bag.
Packaging may depend on clinic volume and available supplies.