[Possibility of stabilizing urea in preparation of control specimens].

9-Triphenylphosphoniomethylphenanthrene chloride (9-TC) is a highly effective antibacterial biochemical stabilizer of the urea, which, used in concentrations 0.6 to 2.45 mmoles/liter, stabilizes its content in the serum for 990 days. Control specimens are prepared as follows: 100 ml of human or animal blood serum is added to 900 ml of 1.82 mmole aqueous solution of 9-TC, mixed, 24 h stored at 4-8 degrees C, and centrifuged. The resultant centrifugate is used as reference specimen for controlling urea measurements by the diacetylmonoxime method.