A diagnostic test system for detecting the presence or absence of an analyte within a test sample is provided. For instance, the system may include a swab and a detection unit. The detection unit includes a first component that is capable of receiving the swab, the first component defining an insertion chamber within which a fluid is capable of being retained. The detection unit also includes a second component that defines a detection chamber within which an assay for detecting the presence or absence of the analyte is capable of being contained. The first component is rotatable relative to the second component from an inactive position to an active position. In the inactive position, the fluid remains substantially contained within the insertion chamber. In the active position, the fluid may flow from the insertion chamber to the detection chamber and contact the assay.