Chloride, urine

Alternate test name

Electrolyte

Lab area

Clinical Biochemistry - General

Method and equipment

Equipment : Roche Cobas Pro ISE

Method : Test principle An Ion‑Selective Electrode (ISE) makes use of the unique properties of ion‑selective membrane to develop an electrical potential (electromotive force, EMF) for the measurements of ions in solution. Selective membrane is in contact with both the test solution and an internal filling solution. Due to the selectivity of the membrane, only the ions to be measured contribute to the EMF. The membrane EMF is determined by the difference in concentration of the test ion in the test solution and the internal filling solution. The EMF develops according to the Nernst equation for a specific ion in solution: The complete measurement system for a particular ion includes the ISE, a reference electrode and electronic circuits to measure and process the EMF to give the test ion concentration.

Expected turn-around time

STAT/ Urgent: 4 Hours Routine: 24 Hours

Shipping information

Background and clinical significance

Intended use The ISE analytical unit of the cobas c systems is intended for the quantitative determination of sodium, potassium and chloride in serum, plasma or urine using ion‑selective electrodes.

Chloride measurements are used in the diagnosis and treatment of electrolyte and metabolic disorders such as cystic fibrosis and diabetic acidosis.

Physiological significance: Electrolytes are involved in most major metabolic functions in the body. Chloride is the major extracellular anion. Similarly to the other ions, common causes of decreased chloride include reduced dietary intake, prolonged vomiting and reduced renal reabsorption as well as some forms of acidosis and alkalosis. Increased chloride values are found in dehydration, kidney failure, some forms of acidosis, high dietary or parenteral chloride intake, and salicylate poisoning.