For Lab Professionals
Capitainer®qDBS and Capitainer®B Vanadate sampling solutions can be easily adopted by any laboratory in six simple steps.
Capitainer®B is designed for finger-pricking, i.e. using fresh blood. However, you might want to start your validation experiments with venous blood and pipetting it to the cards in the lab. There are some aspects to consider when you do this:.
- Do not use blood older than three days stored in the refrigerator and let blood come to room temperature before using it on the cards.
- All blood samples should be well mixed using a rocker prior to application to the card.
- If you use a syringe dispenser, you should make sure to apply blood to the cards within 5 minutes from last time mixing.
- 30µl is the recommended volume to apply, which corresponds to the volume of a big drop of finger blood.
- Lyophilized blood products may not work.
- Make sure that the DBS disc is completely dry before removal. A wet disc might not detach correctly from the card.
We have designed our paper based shipping method to reduce waste and minimise the carbon footprint of your workflows. The packaging approach follows the CDC triple packaging guidelines for DBS specimen collection. We strongly recommend the use of our shipping method.
However, if your analytes are sensitive to humidity and / or temperature, alternative approaches such as storing the samples in aluminium coated plastic bags and inclusion of desiccant pouches should be considered. The approach taken for individual analytes will need to be appropriately validated.
For more guidance, please check the extensive literature on DBS.
The paper “Dried blood spots: Effects of less than optimal collection, shipping time, heat, and humidity” gives an introduction to the topic.
The disc containing the blood is easily accessed from the reverse of the card by peeling away the protective tabs.
The discs can be removed manually with tweezers and put it into a suitable tube or plate for extraction. We recommend a flat tip tweezer.
Capitainer also provides a semi-automated puncher system. The puncher is equipped with a barcode scanner, optical detection of the disc in the wells and an optional cleaning step for the puncher head between each sample. The semi-automated puncher saves time and also ensures traceability of each sample for the downstream analysis process.
The Capitainer puncher system is calibrated at delivery for your 96-well plate of choice.
We highly recommend use of the automated puncher solution for larger projects and/or frequent analysis.
Read more about the puncher at the product page.
After collection of the disc, the sample is eluted. The choice of elution protocol and buffer is dependent on your analyte and downstream analysis. Published methods with conventional DBS samples are also applicable for Capitainer®qDBS and could serve as a guideline.
Add your buffer of choice to the tubes or plate wells containing the discs. 100-150µl is a guide, but must be adjusted depending on concentration and volume requirements. This gives a 10-15 times sample dilution to calculate for in downstream analysis. The discs absorbs approximately 20µl diluent that will not be recovered with the standard protocol. We do not recommend lower elution buffer volume than 50µl for an efficient elution process.
Gently agitate the tube/plate containing disc and extraction buffer for 30-60 minutes and then transfer the liquid to a clean tube or plate.
To reduce the diluent volume and introduce a clean-up step, the use of spin columns/plates to elute the sample might be considered. This has the benefit of also recovering most of the 20µL liquid absorbed by the disc.
1.Choose appropriate filter for your analyte
2.Add the qDBS disc to the column
3.Apply buffer, gently agitate for 60 min
4.Spin down the eluate, discard column + disc
For automation setup, the use of this extraction principle has the benefit of producing an eluate without the DBS disc remaining at the bottom of the wells. This means that pipetting robots potentially can go down deeper in the well and thereby pipette from lower volumes.
Certain liquid handling robots can also handle filter plates, thereby enabling a fully automated workflow for assay setup downstream of the disk removal.
The eluted samples are ready for analysis on your selected platform. Among the techniques and platforms used with samples from Capitainer are:
The review “State of the Science in Dried Blood Spots” describes a range of analytes measurable in DBS samples. These approaches should also be applicable to the quantitative analysis of Capitainer®qDBS samples.
For venous sampling, large volumes of blood are discarded, since only small volumes are typically used for analysis. Self-sampling with Capitainer® reduces this waste. Please, always follow your local regulations regarding waste handling of dried samples.
If not discarded, samples are often stored in biobanks. Venous samples are typically transferred to tubes and frozen at -80 °C. This is costly, consumes a lot of energy and takes up a large amount of space. qDBS samples offer the possibility to biobank samples in a simpler and more cost efficient way.
The paper “Stability of Proteins in Dried Blood Spot Biobanks” discusses the possibilities.