A method of identifying the presence of an analyte may include providing an in vitro test device and a test swab; obtaining a sample using the test swab; transitioning the locking member from the first configuration to the second configuration; advancing the plunger into the housing to pierce the one or more reagent pouches in the reagent region to cause reagent therein to be released and mix; inserting the test swab with obtained sample into the interior of the plunger; rotating the in vitro test device and disposing it on its plunger base; and determining whether the analyte is present. The in vitro test device may include a plunger, a housing, one or more reagent pouches disposed in the housing, a lateral flow test strip, and a locking member having configurations that either allow or prevent reagent in the one or more reagent pouches from being released.