Quantitation of hemoglobin with the Vision Analyzer by use of the alkaline hematin reaction

Blood is drawn into capillary tubes containing saponin and the tubes placed into the reagent packs. Hemoglobin is denatured by mixing the hemosylate with a reagent containing lithium hydroxide and a non-ionic detergent. The absorbance is measured bichromatically at wavelengths of 577 and 633 nm. The calibration curve is stable and can be stored for at least 30 days. There are no interferences from fetal hemoglobin, glycosylated hemoglobin (20 percent), hemoglobin S, samples with hematocrits up to 0.55, paraproteins, and lipemia. Specimens with rouleau formation, nucleated and fragmented red blood cells, target cells, ovalocytes, teardrop cells, spherocytes, leukocyte counts of 29 X 10(9) per L and reticulocyte counts of 0.32; Howell-Jolly bodies did not interfere with the assay. The within run and between run precision gave average coefficient or variations of 2.3 and 1.9 percent, respectively. Comparison of the hemoglobin results obtained in 149 samples with the Vision (y) and Coulter Counter System (x) gave r = 0.987, Y = 1.01X - 1.89 g per L.