An integrated microfluidic blood sampler for determination of blood input function in quantitative mouse microPET studies

In this study, we developed and constructed a blood sampling system on an integrated microfluidic platform to withdraw sub-microliter blood samples from mice up to a rate of one to two samples per second. On one microfluidic chip, eighteen blood samples can be collected on designated wells and can be retrieved later for further analysis. The chip is flushed with Heparin lock flush between sample collections. The device is remotely controlled by a user-friendly interface and can be programmed to take samples at specific time interval. Preliminary results show that both saline solution and FDG blood samples (∼220 nano-liter/sample) can be taken with a consistent volume (variation < 2.2% s.d.) at a rate of one sample per second. Although the volumes are small, the FDG activities in blood samples are detectable with low variability (<1.2%). Our study demonstrates the feasibility of deriving input function from mice using a microfluidic blood sampling device. The blood loss (<100 μl) and the impact on physiological change is expected to be minimized.