Abstract: The disclosed embodiments relate to method, system and apparatus for assay testing. In an exemplary embodiment, the disclosure relates to a cartridge for testing an assay. The cartridge includes a sample reservoir to receive a mixture of a plurality of target particles and a ferrofluidic solution; a capture region formed on the cartridge; a fluidic channel to communicate the mixture between the sample reservoir and the capture region; a magnetic ferrofluidic solution positioned inside the fluidic channel; and at least one pneumatic valve to communicate a quantity of the mixture from the sample reservoir. The magnetic ferrofluidic solution is excitable in response to an externally applied electromagnetic field to affect the ferrofluidic solution in the mixture.