[Possibilities of chemical germ-conservation and its meaning for the bacteriological urine diagnosis]

To estimate the germ-preserving effect of 15 percent disodium-calcium-ethylene-diamine-tetraacetate, 1.8 percent boric acid, 20 percent dimethyl sulfoxide and 3 solutions containing 0.001 percent merthiolate and 15 percent glycerin, 2 percent ethylene-diamine-tetraacetic acid and 15 percent glycerin, and 30 percent NaCl and 3 percent polyvinyl pyrrolidone respectively, comparative investigations were conducted in 4 series comprising a total of 400 urine samples. Boric acid, which is very easy to use, proved the most effective. After 24-h storage at room temperature of boric-acid-preserved urine samples with bacterial counts of over 10-4 per ml, the results were false-negative in 2-4 percent; after 48 h the rate was 6-8 percent and after 72 h nearly 10 percent. There were no false-positive results.