The present invention provides microfluidic devices and methods for measuring blood. The microfluidic devices of the present invention include an inlet port adapted and configured to receive a fluid sample, a microfluidic flow path in fluidic communication with the inlet port, an outlet in fluidic communication with the microfluidic flow path, the outlet: having a smaller cross-sectional area than the microfluidic flow path; and adapted for communication with a pressure sink. The microfluidic devices further include a priming circuit in fluidic communication with the microfluidic flow path such that when a priming fluid is applied under pressure to the priming circuit, the priming fluid will flow through the microfluidic flow path to the inlet port due to low resistance to laminar flow in the microfluidic flow path relative to the outlet.
展开▼