Which of the following is a common preanalytical error related to collection technique?

Prepare for the Clinical Chemistry Automation Test with a comprehensive practice quiz. Study with detailed explanations and multiple choice questions to enhance your understanding and boost your confidence. Ace your exam with our prepared material!

Leaving the tourniquet on too long is a collection technique error that directly affects the sample before it’s analyzed. When the tourniquet is kept tied for an extended period, blood pools in the distal veins and the plasma becomes more concentrated relative to the cells. This hemoconcentration changes the measured levels of many analytes, often giving artificially higher values for substances like potassium and other components, and can also alter hematocrit and protein concentrations. Because this issue arises from how the blood is drawn, it’s categorized as a preanalytical collection technique error. Proper practice is to release the tourniquet as soon as the venous blood flow is established and to complete the draw promptly to avoid these concentration effects.