Ace the CAMLPR Chemistry Challenge 2026 – Unleash Your Inner Scientist!

Potassium measurement is highly sensitive to pre-analytical conditions because potassium is mostly inside cells, so any process that damages cells or concentrates the sample will skew the result. Hemolysis directly releases potassium from red cells, producing a falsely high value. Exposing whole blood to cold can promote cell membrane disruption and leakage, again tending to raise the potassium reading. Delayed centrifugation keeps cells in contact with plasma longer, increasing the chance of potassium leaking into the serum or plasma. Leaving the tube open can allow evaporation, which concentrates solutes and can falsely raise the measured potassium. Extreme temperatures, particularly heat, can cause sample instability or cell damage that may lower the reading in some situations, so it’s included as a potential source of error. Hemoconcentration—loss of plasma water from the sample—also raises the concentration of potassium. Because all of these factors can improperly alter potassium results, the comprehensive set that includes them is the best representation of pre-analytical issues to watch for.