Aqueous assayed control fluids for verifying the integrity of newly received cartridges. i-STAT Level 1, 2 and 3 controls are formulated at three clinicaly relevant levels with known pH and with known concentrations of: • Sodium • Potassium • Chloride • Ionized Calcium • pCO2 • pO2 • Glucose • Lactate • BUN/Urea • Creatinine Each level of controls is packaged in a box of 10 ampules. Control solutions are contained in 1.7ml glass ampules. The control solutions do not contain human serum or serum products, but do contain buffers and preservatives.