Serum urea analysis using the Beckman BUN Analyzer.

A new instrument, the Beckman BUN Analyzer, has been produced for the estimation of urea in microvolume (0-01 ml) of serum or plasma. It requires only a simple two-point calibration for standardization and is suitable for a range of urea levels from zero to 70 mmol/l. The test procedure is simple. After the initial calibration the test sample is injected into the testing chamber and a digital result of the urea concentration is displayed. Serum urea measurements made by this method compared well with those obtained by the Technicon AutoAnalyzer method over the entire working range. The within-batch coefficient of variation of the method is 5-5%, and less at urea levels of 11 to 44 mmol/l. The between-batch coefficient of variation of the method is 6-9%, and less at urea concentrations of 10 to 47 mmol/l. The BUN Aanalyzer method is a quick and reliable alternative to conventional laboratory methods for serum or plasma urea estimation and is especially useful for urgent investigations of both adult and paediatric patients in the hospital wards and at the outpatient clinics.