What happens if a sodium citrate sample is filled an inch below the fill line?

When a sodium citrate sample is not filled to the appropriate fill line, it can lead to an unacceptable blood to anticoagulant ratio. Sodium citrate acts as an anticoagulant, and the correct volume of blood is crucial for accurate coagulation results. An inch below the fill line significantly reduces the volume of blood relative to the amount of anticoagulant in the tube, which can artificially prolong coagulation times and lead to misleading test results.

In coagulation studies, maintaining the correct blood to citrate ratio is essential to ensure that the clotting factors are adequately preserved for accurate testing. If the volume is insufficient, the anticoagulant will not function as intended, thus rendering the sample unsuitable for reliable testing. Consequently, the sample is deemed unacceptable for coagulation studies when it is not filled to the specified line.