What is the correct ratio of anticoagulant to blood for coagulation procedures?

For coagulation procedures, the correct ratio of anticoagulant to blood is critical to ensure accurate test results. A ratio of 1:9 is standard, meaning that for every part of anticoagulant, nine parts of blood are used. This ratio ensures that there is an adequate volume of blood to allow for proper anticoagulation while still maintaining the integrity of the blood sample for testing.

The use of an appropriate anticoagulant, commonly sodium citrate in this case, is vital for preventing clot formation. This anticoagulant works by binding calcium ions in the blood, which are essential for the coagulation cascade. If the ratio were to be altered significantly, either too much anticoagulant or too little blood could distort the results, leading to inaccuracies in diagnosing clotting disorders.

In coagulation testing, maintaining the proper anticoagulant-to-blood ratio enhances the reliability of tests such as prothrombin time (PT) and activated partial thromboplastin time (aPTT), which are essential for evaluating the coagulation pathway. This standardization is why a 1:9 ratio is consistently the recommended practice.