ISE Calibrator Indirect/Urine for the COBAS INTEGRA ISE module. Used for calibrating the ion-selective electrodes for quantitative determination of sodium, potassium, and chloride in urine and indirect (diluted) serum/plasma samples. Contains defined electrolyte concentrations (25 mmol/L Na⁺, 0.8 mmol/L K⁺, 0.05 mmol/L Li⁺, 19 mmol/L Cl⁻). Ready-to-use liquid format. Content: 1 × 250 mL.