Abstract: A swab is packaged in a tube having an open end and containing a culture-sustaining or bacteria identification liquid at the bottom of a tube, and a plug including a one-way isolating valve located above the liquid and a barrier member forming a leak-proof chamber between the plug and the barrier member. After removal of the swab from the tube and swabbing of a body canal or the like with the absorbent tip of the swab, the swab may be placed back in the tube with the absorbent tip adjacent the plug and within the substantially air-tight chamber. The plug may then be forced downwardly through the liquid by pressing on the end of the swab or another rigid member telescoped within the tube so as to force the liquid up through the valve into contact with the absorbent tip. A closure or cap which may be used to press on the end of the stick or the rigid member then forms a seal at the open end of the tube.