Abstract: Liquid sample collection devices, systems, and methods. In one example, the system includes a liquid collection device, a cap for the liquid collection device, and a sealed reagent liquid container installed in the cap, in which depressing the cap relative to the liquid collection device unseals the reagent liquid container. In another example, the system includes a liquid collector and a collection chamber in which the collection chamber holds a reagent in a sealed condition and the liquid collector is actuable to disrupt a sealing membrane associated with the collection chamber. In another example, the system includes a liquid collector and a collection chamber in which the liquid collector holds a reagent in a sealed condition and in which the liquid collector is actuable to drain the reagent from the liquid collector into the collection chamber.