Comparison of K2 EDTA Anticoagulant and Other Anticoagulants

In the fields of clinical laboratory tests and biomedical research, anticoagulants play a very important role as they prevent blood coagulation for various blood tests and analyses. K2 EDTA anticoagulant is a commonly used one, and compared to other anticoagulants, such as lithium heparin, sodium heparin, and sodium citrate, it has unique properties and characteristics. These anticoagulants differ in their anticoagulation mechanisms, effects on blood cells, applicable test items, as well as stability and storage conditions.

Anticoagulation Mechanisms

EDTA K2 Anticoagulation Mechanism

EDTA (ethylenediaminetetraacetic acid) K2 primarily exerts its anticoagulant effect by chelating calcium ions (Ca²⁺) in the blood. Calcium ions are necessary for the activation of multiple coagulation factors in the blood coagulation process. EDTA K2 forms stable chelates with Ca²⁺, thus blocking the coagulation cascade. This anticoagulation mechanism effectively inhibits blood coagulation without significantly affecting other components in the blood. For example, in routine blood tests, blood samples with K2 EDTA anticoagulant can accurately reflect the quantity and morphology of red blood cells, white blood cells, and platelets because it has minimal direct impact on these cell components.

Heparin Anticoagulation Mechanism

Heparin mainly anticoagulates by enhancing the activity of antithrombin III (ATⅢ). Antithrombin III can inhibit various coagulation factors such as thrombin (Ⅱa), factor Ⅹa, Ⅸa, Ⅺa, and Ⅻa. When heparin binds with ATⅢ, it alters ATⅢ's conformation, significantly increasing its inhibitory effect on coagulation factors, thereby preventing blood coagulation. Heparin has a rapid and strong anticoagulant effect, but its action is relatively complex and may significantly impact some coagulation-related tests, such as APTT (activated partial thromboplastin time) and PT (prothrombin time).

Effects on Blood Cells

Effects on Red Blood Cells

K2 EDTA anticoagulant has minimal impact on red blood cell morphology. Under the microscope, red blood cells anticoagulated by EDTA K2 can maintain their normal shape, allowing for more accurate results in red blood cell-related indices such as red blood cell count, hemoglobin measurement, hematocrit, and red blood cell morphology examination.

Effects on White Blood Cells

K2 EDTA anticoagulant does not affect white blood cell count and size, enabling even distribution of white blood cells within the sample, which facilitates white blood cell differential counting and total count determination. Various types of white blood cells can maintain their normal shape and characteristics in EDTA K2-anticoagulated blood, benefiting accurate identification and classification via blood analyzers. Heparin and sodium citrate may not be as suitable for white blood cell tests.

Effects on Platelets

K2 EDTA anticoagulant can inhibit platelet aggregation, allowing for accurate platelet count. Additionally, it has minimal impact on platelet morphology, which is advantageous for platelet morphology examination. Heparin, on the other hand, may cause platelet aggregation, leading to lower platelet counts and altered platelet morphology, complicating the diagnosis of platelet-related diseases. Platelets may also aggregate to some extent when using sodium citrate as an anticoagulant.

Applicable Test Items

K2 EDTA Anticoagulant Applicable Items

Due to its minimal impact on blood cell morphology and counts, K2 EDTA anticoagulant is suitable for most routine hematology tests, such as complete blood count (CBC) and blood typing. In these tests, EDTA K2 provides stable and accurate blood samples. For instance, in routine blood tests, most laboratories use blood samples with K2 EDTA anticoagulant to ensure accurate measurement of various blood cell indices.

Heparin Applicable Items

Heparin is mainly suitable for items requiring rapid anticoagulation and those with specific coagulation function test requirements, such as antithrombin III activity measurement. It is recommended for use in plasma tests, as well as for blood glucose and electrolyte detection.