Test Overview
Test Methodology

Potentiometric (ISE)

Test Usage

Evaluate electrolyte balance

Reference Range *

<1 year: 3.6 - 5.5 mmol/L, 1-11 years: 3.3 - 5.1 mmol/L, 12-150 years: 3.5 - 5.1 mmol/L.

* Reference ranges may change over time. Please refer to the original patient report when evaluating results.

Test Details
Days Set Up
Daily, 24 hours
Analytic Time

2 hours

Soft Order Code
MiChart Code
  • K
  • Potassium
  • POT
Chemical Pathology
STAT Availability

STAT requests for this test will be performed on a STAT basis (supervisory staff approval is not required).

Specimen Requirements
Collection Instructions

Collect specimen in an SST tube. Centrifuge within 4 hours of collection, aliquot serum into a plastic vial and refrigerate. If specimen cannot be centrifuged at client site, please arrange for delivery to MLabs within 3 hours of specimen collection.

Special Handling

Falsely elevated potassium levels or falsely decreased glucose levels may result when the specimen remains uncentrifuged for more than 4 hours after collection. MLabs requests that samples for potassium and/or glucose collected at the client site be centrifuged or delivered uncentrifuged within 3 hours of collection. If unspun specimens sent for potassium or glucose testing are received without a collection date and time noted, MLabs will make every effort to obtain this information from the client. The specimen will not be rejected for being uncentrifuged; however, the following comment will be added to the report: "Specimen was received uncentrifuged more than four hours after draw. This may cause falsely elevated potassium level or falsely decreased glucose level. Please interpret results accordingly."

Alternate Specimen
Green top (sodium or lithium heparin) tube, Red top tube. [rev 11/09]
Normal Volume
0.5 mL serum
Minimum Volume
0.25 mL serum
Rejection Criteria
Grossly hemolyzed samples are unacceptable for analysis.
CPT Code
Fee Code