Misleading sputum cartons.
Waxed paper sputum cartons obtained from the manufacturers contained very few organisms. Similar cartons which had been stored in hospital wards were often contaminated with hospital dust. This contamination was sometimes sufficiently marked to be misleading. Coliform organisms are particularly liable to cause confusion. Waxed cartons are useful for collecting sputum, but they must be properly stored.
Biomedical Technology↗