Laboratory Medicine

Laboratory Test Catalogue

Potassium (K)

Test Name

Potassium (K)

Specimen Type / Requirements

Container Type = Gold (SST) or Lt Green (PST)

Minimum Testing Volume = 0.5mL Serum or Plasma

Preferred Testing Volume = 1mL Serum or Plasma

Tube must fill to at least ½ or greater of its vacuum capacity

Specimen Handling

Collection Instructions: Serum or plasma, free from hemolysis, collected with or without gel separator. For plasma use lithium or ammonium heparin only. Separate serum or plasma from cells within 2 hours of collection

Write your initials, date and time of collection on the collection label.

Stability: Lytes is stable at room temperature for 24 h, refrigerated for 1 week and frozen at -15 to -20°C for 6 months.

Transportation: Transport at room temperature ASAP.

Laboratory Staff Instructions: Separate serum or plasma from cells within 2 hours of collection.

Sample Rejection Criteria: Gross hemolysis and/or Non sufficient Quantity (Not Sufficient Quantity) will be cancelled.

Reference Value

Age	Normal Range	Abnormality - Critical	Units
0 up to 1 Days	4.5-6.5	< 2.5 or >6.5	mmol/L
1 Days up to Unspecified	3.2-5.0	< 2.5 or >6.0	mmol/L

Test Code

LAB114

Methodology

Indirect Potentiometry

Testing Location

SMH-Biochemistry

Other Information

Last Updated: August 18, 2026