Effects of bacterial contamination of reagent water on selected laboratory tests

The effects of three widely spaced levels of bacterial contamination of reagent water on several chemistry, radioimmunoassay, and coagulation procedures were studied. These included determinations of lactate dehydrogenase, creatine kinase, aspartate transaminase, alkaline phosphatase, blood urea nitrogen, total protein, thyroid-stimulating hormone, digoxin, thrombin time, activated partial thromboplastin time, and prothrombin time. Statistical analyses included calculations of means and coefficients of variation, and analysis of variance, as well as correlation coefficients for test results versus logarithm of bacterial contamination. Statistically and clinically significant differences occurred together only for an elevated level of creatine kinase.