Abstract: A lateral flow test kit includes a cassette and a swab. The cassette comprises a vial of liquid closed by seal; a test strip; a passage leading from the exterior of the cassette to the vial; and a conduit communicating between the vial and the test strip. The swab can be inserted along the passage to cause a tip of the swab to enter the vial and release liquid from the vial. The liquid flows past a head of the swab to extract a sample and deliver it through the conduit 34 to the test strip. The passage may comprise an obstruction, which requires the user to push the swab past it with a force sufficient to penetrate the seal. The obstruction may also prevent removal of the used swab from the cassette. A distal end of the passage may be curved to deflect the tip of the swab towards the seal at a more favourable angle.