High-purity water supplies for biomedical research laboratories

A quantitative bacteriological survey of high-purity water systems used in biomedical research laboratories at the National Institutes of Health revealed great variations among the systems. In general, distilled water had significantly lower contamination levels than deionized water. Interviews with investigators revealed their conceptions about the importance of bacterial contamination in high-purity water and some expectations about bacterial quality. Guidelines are suggested for the use of water from systems of varying quality.