Why is it important to fill blood collection tubes to the correct volume?

Filling blood collection tubes to the correct volume is crucial to ensure the correct ratio of blood to anticoagulant. Anticoagulants are designed to preserve the integrity of the specimen for accurate testing. Each tube is calibrated to work best at a specific blood volume. If the volume is too low, it can lead to an insufficient amount of anticoagulant in the mixture, causing the blood to clot and compromising the sample's viability for tests that require anticoagulation. Conversely, if the volume is too high, it could dilute the anticoagulant and similarly lead to clotting issues.

Properly filled tubes also align with standardized testing protocols that laboratories follow to ensure both the accuracy and reliability of results. Without maintaining these specific ratios, the tests could yield invalid results, which could impact diagnosis and treatment decisions.