Toxin activity assays, devices, methods and systems therefor

A system for conducting a toxin activity assay, the system comprising:

• a microfluidic disk comprising:
• a substrate, wherein the substrate at least in part defines a channel;
• a fluid sample contained in the channel, wherein the fluid sample includes a plurality of beads having complexes formed thereon by action of an active toxin, individual ones of the complexes comprising a capture agent and a labeling agent, wherein the fluid sample further includes free labeling agent;
• a detection region coupled to the channel and defined at least in part by the substrate and containing a density media, wherein the density media has a density higher than a density of the fluid sample and lower than a density of the plurality of beads;
• and
• wherein the channel and detection region are configured to transport the plurality of beads in the fluid sample from the channel through the density media responsive to a centrifugal force, and wherein at least a portion of the free labeling agent is restricted from transport through the density media;
• a motor coupled to the microfluidic disk, the motor configured to receive a motor control signal and spin the microfluidic disk responsive to the motor control signal;
• a detection module positioned to detect a signal from labeling agents included in the complexes, wherein the detection module is configured to generate an electronic detection signal based, at least in part, on the signal from the labeling agent;
• and
• a processing device coupled to the motor and the detection module, wherein the processing device is configured to generate the motor control signal and provide the motor control signal to the motor, and wherein the processing device is further configured to receive the electronic detection signal from the detection module.