Diagnostic analysis of total protein, albumin, white cell count and differential in ascitic fluid

Accurate and precise procedures are described for the measurement of total protein, albumin, white cell count and differential in ascitic fluid. The total protein method (biuret) on the serum chemistry analyser, Bayer-Technicon Chem-1, was calibrated against the biuret reference method in the measuring range from 1-100 g/l, covering serum as well as ascitic fluid values. The albumin method (bromcresol green) on the Chem-1 was calibrated for the measurement range from 1-50 g/l against the new human plasma protein international reference preparations and compared to the nephelometric method on the Beckman Array, which was also calibrated against these reference preparations. A good correlation was obtained for total protein between the Chem-1 (y) and the biuret reference method (x) in 58 ascitic fluids (y = 1.02x -0.3; r = 1.00). A good correlation between the Chem-1 (y) and the Array (x) was also obtained for albumin (r = 0.99). The bromcresol green method, however, which is not fully specific, resulted in significantly higher results (y = 1.32x - 1.3). The immunochemical procedure is considered the more accurate and therefore the bromcresol green method is not suitable for the determination of albumin in ascitic fluids. The white cell count in ascitic fluid can be measured reliably by most haematology analysers if the sample is fresh and homogeneous, but the differential is flagged as a result of differing morphology. Handmade smears from ascitic fluid, however, show uneven distribution of cells and disturbed morphology.(ABSTRACT TRUNCATED AT 250 WORDS)