An apparatus for collecting and combining a sample with a reagent, the apparatus comprising: a container comprising an upper portion defining an opening for receiving the sample and a closed, lower portion comprising a cavity for containing the sample and a reservoir containing the reagent, the reservoir comprising a pierceable membrane; a cap, the cap and the upper portion of the container each comprising complementary threads (108, 208) configured to removably engage the cap with the container to form a seal, the cap further comprising first engagement means; and an insert configured to nest within the container, the insert comprising an upper portion defining an upper opening, the upper portion comprising second engagement means complementary to the first engagement means, wherein the: first engagement means comprises a first plurality of teeth; and the second engagement means comprises a second plurality of teeth and wherein the first plurality of teeth are configured to engage with the second plurality of teeth; and wherein the apparatus further comprises: a lower portion defining a lower opening, the lower portion comprising one or more piercing elements; the insert being movable from a first position to a second position within the container, wherein when the insert is in the first position, the one or more piercing elements are located above the pierceable membrane; and wherein when said apparatus is sealed by twisting the cap onto the container, the first plurality of teeth of the first engagement means engage with the second plurality of teeth of the second engagement means causing the insert to rotate and move downward within the container from the first position to the second position, whereby the one or more piercing elements disrupt the pierceable membrane to allow fluid communication between the cavity and the reservoir. a container comprising an upper portion defining an opening for receiving the sample and a closed, lower portion comprising a cavity for containing the sample and a reservoir containing the reagent, the reservoir comprising a pierceable membrane; a cap, the cap and the upper portion of the container each comprising complementary threads (108, 208) configured to removably engage the cap with the container to form a seal, the cap further comprising first engagement means; and an insert configured to nest within the container, the insert comprising an upper portion defining an upper opening, the upper portion comprising second engagement means complementary to the first engagement means, wherein the: first engagement means comprises a first plurality of teeth; and the second engagement means comprises a second plurality of teeth and wherein the first plurality of teeth are configured to engage with the second plurality of teeth; and wherein the apparatus further comprises: a lower portion defining a lower opening, the lower portion comprising one or more piercing elements; the insert being movable from a first position to a second position within the container, wherein when the insert is in the first position, the one or more piercing elements are located above the pierceable membrane; and wherein when said apparatus is sealed by twisting the cap onto the container, the first plurality of teeth of the first engagement means engage with the second plurality of teeth of the second engagement means causing the insert to rotate and move downward within the container from the first position to the second position, whereby the one or more piercing elements disrupt the pierceable membrane to allow fluid communication between the cavity and the reservoir. a lower portion defining a lower opening, the lower portion comprising one or more piercing elements; the insert being movable from a first position to a second position within the container, wherein when the insert is in the first position, the one or more piercing elements are located above the pierceable membrane; and wherein when said apparatus is sealed by twisting the cap onto the container, the first plurality of teeth of the first engagement means engage with the second plurality of teeth of the second engagement means causing the insert to rotate and move downward within the container from the first position to the second position, whereby the one or more piercing elements disrupt the pierceable membrane to allow fluid communication between the cavity and the reservoir.