Haemolysis

Red blood cells can burst when blood is squeezed hard out of a finger, shaken, kept too warm or too cold, or left too long before it reaches the laboratory. Their contents, including potassium and the red pigment haemoglobin, then mix with the serum and colour it pink or red.

Some values are affected more than others, and potassium is the best-known example, because the cells hold far more of it than the serum does. When a laboratory sees haemolysis it may still report some values and mark others as not measurable.

For a business selling blood tests the practical questions are how often samples are affected and who tells the customer. Ask a supplier how it flags a damaged sample and who arranges a new collection.

Aniva flags a sample that cannot be measured in your console and arranges a redraw. In this glossary, Präanalytik covers the handling that prevents haemolysis, and Serum tube explains the tube where it is usually seen.