Specimen Requirements


Potassium, Plasma

Specimen Requirement

Collect lithium heparin or sodium heparin, centrifuge and transfer 1.0 mL plasma to a screw top plastic vial, indicate sample type on tube and send.


Ion Selective Electrode (ISE)


Room temp: 7 days, Refrigerated: 7 days, Frozen: 28 days

Reference Range

The reference range is determined by the performing laboratory and will show on the report.


1-2 days performed Monday-Saturday

Clinical Use

False elevations of potassium may be due to hemolysis or rupture of platelets during coagulation process. The use of plasma potassium levels should be limited to those patients with spuriously elevated or depressed potassium levels due to blood samples left at room temperature, in patients with chronic lymphocytic leukemia with very high WBC counts (false decline), and those with thrombocytosis (increased platelets) with counts in excess of one million (false elevation).

Test Code