Use of the replica-plate technique in studies of toxicity of metals and plastics to bacteria.

A study was made on the efficacy of commonly used test methods to provide useful data concerning toxicity of construction materials to bacteria. Tests such as growth and storage of liquid cultures, which are based on plate counts, appeared to be less efficient in providing interpretable data than were tests which used solid media. The conjunctive use of zone inhibition and an adaptation of the replica-plate technique used in bacterial genetics supplied as much information as other tests, but these solid-media tests were easier to perform, accommodated more test samples per unit of bacterial culture, and the data were more easily understood.