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. 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