Chloride (CL)

CPT Code: 82435
Specimen: Serum or heparinized plasma
Volume: 1 mL
Minimum Volume: 0.5 mL
Container: Red-top tube, gel-barrier tube, or green-top (lithium heparin) tube
Methodology: Ion-selective electrode (ISE)
Collection: Serum is obtained by collecting blood in an untreated blood collection tube.  The sample should stand for 30 minutes to allow the clot to form prior to centrifugation.

Specimen tubes should be centrifuged unopened and the serum or plasma should be separated within one hour after venipuncture.

Sera or plasma separated from cells that are stored for several hours prior to analysis should be inspected for delayed fibrin clot formation.  If delayed clot formation is detected or suspected, the sample should be centrifuged before analysis.

Whole blood specimens cannot be analyzed.

Reference Range: 98-107 mmol/L


Temperatures Period
Room Temperature 1 week
Refrigerated (2-8 ⁰C)  1 week


Use: Chloride, an electrolyte, is involved in maintaining the normal amount of water and the acid-base balance in body fluids.  Chloride generally increases and decreases with plasma or serum sodium.
Clinical Significance:

Chloride is increased in dehydration, with ammonium chloride administration, with renal tubular acidosis (hyperchloremic metabolic acidosis) and with excessive infusion of normal saline. Differential diagnosis of acidemias and alkalemias. Chloride is higher in hyperparathyroidism than in some of the other causes of hypercalcemia, but a great deal of overlap exists.

Chloride is decreased with overhydration, congestive failure, syndrome of inappropriate secretion of ADH, vomiting, gastric suction, chronic respiratory acidosis, Addison disease, salt-losing nephritis, burns, metabolic alkalosis, and in some instances of diuretic therapy.

Causes for Rejection:  

Improper labeling

Interfering Substances: Citrate at a test concentration of 52.9 mmol/L increases chloride by 57 mmol/L.