We’ve developed a microfluidsystem based technology that offers a solution for Self Sampling.
Capitainer qDBS uses a combination of paper and polymer microfluidics to meter a 10 µl fixed volume from an undefined volume of finger prick blood. After applying a drop of blood to the inlet, a metering channel in the device is automatically filled. A valve composed of a thin dissolvable membrane then opens up 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. The sample is allowed to dry forming a high quality DBS sample suitable for quantitative analysis.
The metering mechanism employing thin dissolvable films was first demonstrated by G. Lenk et al
The technology is precise. In an experiment using caffeine as tracer molecule, the Capitainer qDBS demonstrated a volume CV (n=20) of 2,84 % where as a standard manual displacement pipette demonstrated a CV of 6,25 %.
Manual Pipetting of Blood vs Capitainer qDBS Collection
- EDTA-blood was collected from a coffee drinker by venous puncture
- 25 µL of blood was applied to 20 Capitainer qDBS 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 qDBS 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