What color-topped evacuated tube is appropriate for electrolyte testing?

The color-topped evacuated tube appropriate for electrolyte testing is green. Green-topped tubes contain heparin, which is an anticoagulant that helps to preserve the integrity of the plasma for testing electrolytes. This is crucial because electrolytes such as sodium, potassium, and chloride need to be measured in plasma to provide accurate results.

Using a tube with an appropriate anticoagulant is essential for maintaining the stability of these analytes, and heparin is effective for this purpose, allowing healthcare providers to obtain reliable electrolyte levels promptly.

In contrast, red-topped tubes typically contain no anticoagulant and are used for serum tests, which are generally not suitable for electrolyte testing that requires plasma. Yellow-topped tubes often have additives for blood cultures or other specific tests. Purple-topped tubes contain EDTA, which is also an anticoagulant but is mainly used for hematology tests rather than electrolyte analysis.