We’ve developed a microfluidsystem based technology that offers a solution for Self Sampling.
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 %.
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
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