Abstract
1623
Objectives: For quantitative analysis with PET data, the input function directly obtained from measuring radioactivity in whole blood or plasma samples is desired. In small animal study, the manual sampling method results in low temporal resolution and excessive blood lost that may affect subject’s physiological condition. In this study, a continuous nanovolumetic blood sampler using microfluidic technology was developed to address these problems.
Methods: The microfluidic chip blood sampler includes a main chamber, integrated peristaltic pump, three inlets (blood, Heparin lock flush and Argon gas) and two outlets (sampling and waste-line). It is fabricated with poly(dimethylsiloxane) (PDMS) which allows precise control of the pneumatic valves in the chip. These valves are actuated through two eight-channel, solenoid valve manifolds. Blood samples are flushed from the chip into a length of plastic tubing by Heparin lock flush fluid and separated by gas bubbles generated by the peristaltic pump. The samples in the tubing were individually sealed, separated by cutting, and transported to a well-counter for activity measurement.
Results: The performance was evaluated with a simulation test using simulated blood source (~300μCi FDG in 10ml sterile water) and two real FDG mouse studies. The sample size of 351nl±3.1% was measured by a sequential collection of 20 samples with repeated five times in the simulation test. In mouse studies, 28 samples were obtained by 2sec for each sampling procedure at desired sampling time points.
Conclusions: We developed a microfluidic device that can be used to obtain nanovolumetric blood samples for small animal studies automatically. With this device, excessive blood loss can be reduced and the sampling temporal resolution improved.
Research Support: The work was supported by UC bio05-10510 and DOE DE-FC03-02ER63420 grants.
- Society of Nuclear Medicine, Inc.