Performing assays
The SpinX cards contain several rows of dosimeters, separated by multiplexers. Any assay or set of assays can be built up by moving the appropriate volumes of liquid to specific destinations, where they are mixed together before using the result in the next step.

As an example, consider the case of samples A and B to be tested in assays X and Y. For drug screening, A and B may be two compounds, at the concentration for which they need to be assayed, and assays X and Y may require two different enzymes “reagent X” and “reagent Y”, along with a common substrate shown as “reagent”.

To initiate the enzymatic reaction in the presence of the presumed inhibitor, well-defined volumes of compound, enzyme, and substrate have to be mixed together. The centrifugal force moves the liquid from the top to the bottom, through any available path. As soon as VLV connections are created between the two sides, additional paths become available for the liquid to follow downward.