Specific Gravity of Whole Blood in Cynomolgus Monkeys (Macaca fascicularis), Squirrel Monkeys (Saimiri sciureus), and Tamarins (Saguinus labiatus) and Total Blood Volume in Cynomolgus Monkeys

Blood collection is a common laboratory procedure in animal experiments. The purpose of this study is to establish baseline data for two essential hematologic parameters, total blood volume (TBV) and specific gravity of blood (SGB), of nonhuman primates. The SGB was determined by dropping samples of whole blood into cupric sulfate solution. The values for the mean SGB 1 standard deviation are: cynomolgus monkeys, 1.0526 0.0019 [males (n = 39), 1.0531 0.0017; females (n = 48), 1.0522 0.001]; squirrel monkeys, 1.0555 0.0037 [males (n = 56), 1.0581 0.0027; females (n = 76), 1.0536 0.0032]; and tamarins, 1.0582 0.0020 [males (n = 13), 1.0582 0.0023; females (n = 17), 1.0581 0.0018]. To determine the TBV, blood was collected in tubes containing 1.5 mg EDTA after intravenous injection of Evans Blue solution. The TBV was obtained after correcting for the hematocrit and the dilution factor of the Evans Blue solution. The formulae were established to estimate TBV by referring to body weight (BW). There was no significance between TBV and BW in male monkeys weighing more than 6 kg.