Potassium, Plasma Test
This test measures the concentration of potassium in a plasma sample, collected in a lithium heparin tube and analyzed using an ion selective electrode. It is used in specific situations where a standard serum potassium result may not be accurate.
About this test
Potassium, Plasma reports the concentration of potassium using a plasma sample rather than serum, collected in a lithium heparin (green-top) tube and measured by ion selective electrode.
Use of this plasma-based version is limited to particular situations: when a blood sample has been left at room temperature and could show a spuriously elevated or depressed potassium level, in people with chronic lymphocytic leukemia and very high white blood cell counts, which can cause a false decline, and in people with thrombocytosis with platelet counts over one million, which can cause a false elevation. False elevations can also result from hemolysis or platelet rupture occurring during the coagulation process, which is part of why a clinician may prefer the plasma method over serum in these situations.
Who might consider this test?
- In the presence of a very high white blood cell count or a very high platelet count
- Situations that can distort a standard potassium result
Test details
| Quest code | 11014 |
|---|---|
| Methodology | Ion Selective Electrode |
| Sample type | 1 mL plasma |
| Collection | Quest patient service center |
Reference range
3.4-4.8 mmol/L
Reference ranges are general guidance. The range printed on your own laboratory report is the one that applies to your result.
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Quest resources
Additional details
What this test looks at
The test reports a single value: the concentration of potassium in the blood, measured from a plasma sample rather than serum. Results can be affected by handling -- a sample left at room temperature, or an unusually high white blood cell or platelet count, can each distort a standard result, which is part of why this plasma-based version exists as an alternative.
Order online and a physician order is included — no doctor's visit and no insurance needed. Your sample is collected at a Quest Diagnostics patient service center.
Laboratory results should always be interpreted by a licensed clinician who knows your health history. This page is information about a test, not medical advice.
Frequently asked questions
What does Potassium, Plasma measure?
It measures the concentration of potassium in a plasma sample, using an ion selective electrode method.
How is the sample collected?
Through a blood draw, collected in a lithium heparin (green-top) tube.
Do I need to prepare for this test?
No preparation instructions are listed for this test, though people follow any instructions their ordering clinician provides.
Why would plasma be used instead of serum for potassium?
Use of this plasma-based version is limited to specific situations, such as a sample left at room temperature, a very high white blood cell count, or a very high platelet count, each of which can distort a standard serum result.
How much does the Potassium test cost?
The cash price at Celio Health is $15. That covers the physician's order and sample collection at a Quest patient service center — no insurance is needed and there's no separate doctor's visit to pay for.