What is the Difference Between EDTA and Sodium Citrate?

EDTA (Ethylenediaminetetraacetic acid) and Sodium Citrate are both anticoagulants used in blood collection tubes to prevent blood clotting. However, they have different purposes and effects on blood samples:

1. Purpose: EDTA is primarily used for hematologic tests, while Sodium Citrate is used for coagulation testing and as a test agent for factors V and VIII.
2. Effect on Platelets: EDTA blood samples can be used for platelet counts and have a stable platelet count after 1 hour of standing at room temperature. In contrast, citrated samples show a significant drop in platelet count after 1 hour, which continues up to 4-6 hours.
3. Calcium Chelation: Both EDTA and Citrate remove calcium from the blood by chelating it, which is essential for blood coagulation. However, Citrate's effect is reversible, allowing calcium to be added back to study coagulation under controlled conditions.
4. Types of Anticoagulants: EDTA is an aminopolycarboxylic acid, while Sodium Citrate is an inorganic compound with sodium cations and citrate anions in different ratios.

In summary, EDTA and Sodium Citrate are both anticoagulants, but they serve different purposes in blood testing and have varying effects on blood samples and platelet counts.

Comparative Table: EDTA vs Sodium Citrate

EDTA (ethylenediaminetetraacetic acid) and sodium citrate are two chemical compounds with different properties and applications. Here is a table highlighting the differences between them:

Both EDTA and sodium citrate exhibit chelating properties, which means they can bind and sequester metal ions. However, EDTA has a broader spectrum of metal ion binding, while sodium citrate has a specific affinity for calcium ions. In the medical field, EDTA is used for hematologic tests and treating heavy metal poisoning, while sodium citrate is used as a coagulation test agent and an anticoagulant. In the food industry, sodium citrate is used as a flavoring or preservative, while EDTA is not.