A disposable blood analysis cartridge may include a sample collection reservoir, an absorbance measurement channel, and an optical light scattering measurement channel. One or more valves may be disposed between the sample collection reservoir and the absorbance measurement channel and/or the optical light scattering measurement channel. A negative pressure may be applied to the cartridge to pull sample from the sample collection reservoir through the one or more valves and into the absorbance measurement channel and/or the optical light scattering measurement channel. Once the sample is pulled into the absorbance measurement channel and/or the optical light scattering measurement channel, the one or more valves may be closed. With the one or more valves closed, and in some cases, a pusher fluid may be provided to push the fluid sample to other regions of the disposable fluid blood analysis cartridge.