Bacteria Traps

devices to trap microorganisms suspended in air in order to determine the extent and nature of bacterial contamination of the air in hospitals, homes, and industrial areas. In traps of Iu. A. Krotov’s system, air is drawn through a slit and then strikes a revolving Petri dish with a solid nutrient medium. In other traps, air is drawn through a liquid (water, nutrient broth) or dry (cotton) absorbing medium. In traps of S. S. Rechmenskii’s system, bacteria are absorbed by small drops of sprayed liquid which settle on the walls of the device. Contamination is determined by cuituring the liquid (or dry medium) that traps the microbes on nutrient mediums.