Rapid turbidity test for diagnosis of uremia.

Abstract

The quantitative determination of urea nitrogen levels in blood is often technically difficult and time-consuming. In many instances, such as night emergency work, office practice, and preoperative screening, it would be sufficient merely to know that the blood urea nitrogen level is within normal limits. Abnormal findings would be followed up with more quantitative measurements. A spot test using Ehrlich's aldehyde reagent has not proved satisfactory in our hands, especially under artificial light. The selective precipitation of urea by xanthydrol has been applied to the quantitative determination of urea nitrogen levels in blood, but the methods are too exacting for routine clinical use. By proper adjustment of acidity and xanthydrol concentration, a test has been devised that accurately detects elevated levels of urea nitrogen in the blood. The test is done directly on plasma or serum, uses stable reagents, and requires only five minutes to perform. REAGENTS Acetic Acid, 50%.—Mix