Performance characteristics of the Coulter Kem-O-Lab.

We evaluated the performance characteristics of the Coulter Kem-O-Lab for the measurements of calcium, inorganic phosphate, total protein, albumin, glucose and urea nitrogen in serum. The precision on replicates agreed with those claimed by the manufacturer. All methods showed acceptable total precision measured over a four-week period, except for urea nitrogen. There was significant correlation between the Kem-O-Lab and routine methods, but the slope was significantly different from unity for calcium, total protein and urea nitrogen indicating a bias in their determinations. While turbidity and hemoglobin significantly interfered with measurements in all methods, bilirubin interference was observed only for total protein and glucose. There were no interferences due to any of the nine drugs tested.