Abstract: This invention relates to a method and device for collecting a Mycobacterium complex species, such Mycobacterium tuberculosis (MTB) from the oral cavities of particularly children and infants. A device is provided which has a distal end and an operative end portion manufactured from a parent polymer which has been functionalised with a chemical compound having an affinity to the Mycobacterium complex species to collect same such that the presence thereof in the sample can be detected. The invention further extends to a method of preparing biological material obtained from such collected sample.