EFFECTS OF STORAGE TIME AND TEMPERATURE ON IONIZED CALCIUM-CONCENTRATION IN EQUINE BLOOD, PLASMA, AND SERUM

Stability of ionized calcium (Ca2+) concentrations and pH values in equine venous samples (n = 12 in each group) stored at 4 C for 3, 9, 24, and 48 hours (blood, plasma, and serum) or for 240 hours (plasma and serum), and at -20 C for 240 hours (plasma and serum), was studied. Storage of equine blood, plasma, and serum samples at 4 C for up to 48 hours and of serum samples at 4 C for up to 240 hours, despite appreciabile pH changes, was associated with < 1.5% change in blood, plasma, and serum Ca2+ concentrations. Therefore, Ca2+ concentration in equine blood, plasma, and serum samples stored up to 48 hours and in serum samples stored up to 240 hours at 4 G is of diagnostic use.