A microfluidic circuit cartridge for a complete blood count, including analyses of red blood cells. Various parameters of the red blood cells may be attained. The cartridge may have sphering mechanism which has a channel or loop with a configuration for reducing or eliminating cell settling. The channel or loop may incorporate a combination of straight and curve paths in the context of gravity. The channel may alternatively have a hydrophilic or hydrophobic inside surface. Again alternatively, the channel may have an electro-wettable inside surface. Or, the channel may be subject to an electric or magnetic field. There may also be a mechanism for reducing or eliminating clumping of a sample.