We’ve developed qDBS technology, a microfluidic technology that offers a solution for easy and accurate Self Sampling.
In Capitainer®B a double valve solution is applied to discard excess blood and deliver the metered 10µL to the sample disc.
All Capitainer blood sampling cards are built on our qDBS technology. It uses a combination of paper, polymer microfluidics and thin water-soluble membranes to meter a fixed volume of blood. After applying blood to the inlet, a metering channel in the device is automatically filled and the blood is transferred to a pre-cut DBS paper disc. The metering mechanism employing thin dissolvable films was first demonstrated by G. Lenk et al
In the 10µL version, one blood drop is added to the inlet and a double valve solution is applied where a thin dissolvable membrane opens up after blood application and removes excessive blood at the inlet. Subsequently, a second membrane opens up , allowing for transfer of the metered blood volume onto the sample collection disk at the outlet.
In Capitainer®B 50 a single valve solution is applied and multiple drops of blood can be added before the metered 50µL is transferred to the sample disc.
The 50µL version applies a single valve solution with another filling mechanism, to allow application of multiple drops.
The sample is allowed to dry forming a high quality DBS sample suitable for quantitative analysis.
Manual Pipetting of Blood vs Capitainer® Collection
- EDTA-blood was collected from a coffee drinker by venous puncture
- 25 µL of blood was applied to 20 Capitainer® channels
- For reference 10 µL of blood was applied by manual displacement pipetting to 20 discs removed from Capitainer®qDBS devices
- Caffeine concentration was measured in all samples by an accredited LC-MS/MS method
- Caffeine concentration coefficient of variation for Capitainer® was 2,84% vs 6,25% for manual pipetting
Source: Evaluation study by Dr Olof Beck, Analysis of caffeine by LC-MS/MS method. 2020 March 16
Similar results were obtained in a study by Spooner et al