EDTA Tubes: Meaning and Difference Between K2 & K3 EDTA
EDTA, an acronym for ethylenediaminetetraacetic acid, is present in the vacuum blood collection tube. It is an anticoagulant that aids in stopping the blood clotting process and is generally used to separate metal ions from the mixture. EDTA blood collection tube is used for several hematology procedures and, most importantly, CBC.
Moreover, it is possible to keep the blood sample in the EDTA tube at 4 degrees Celsius for 24 or 36 hours before processing. In addition, you can also store the sample for up to 20 days but at a temperature of -80 degree Celsius.
Difference Between K2 EDTA and K3 EDTA
The primary difference between K2 and K3 EDTA is the presence of chelated potassium ions, wherein K2 EDTA has two and K3 EDTA has three ions, respectively. In addition, K3 EDTA does not affect MCV, i.e., the mean corpuscular volume of the RBCs (red blood cells) at higher concentrations. On the contrary, the K2 EDTA increases the mean corpuscular value of the RBCs at greater concentrations.
Dipotassium Ethylenediaminetetraacetic Acid, commonly known as K2 EDTA, is a rich anticoagulant commonly used to store blood in the purple or lavender blood collection tubes for CBC (complete blood counts). Generally, the whole blood is stored in these collection tubes, and K2 EDTA blood collection tubes include two ions of potassium bonded to the EDTA molecule.
In addition, this chelating agent can sequester ions like ferric and calcium in a mixture, ultimately decreasing their reactivity as calcium ions are essential for coagulation. This is how EDTA prevents blood clotting.
K3 EDTA has three ions of potassium connected to the EDTA and is commonly used for hematological arrays. This additive is liquid which ultimately leads to specimen dilution.
However, K2 EDTA is generally preferred as an anticoagulant since EDTA’s higher concentration in K3 reduces RBCs.
Wrapping Up
Using EDTA vacuum blood collection tubes accurately is crucial for appropriate laboratory tests. The primary difference between these anticoagulants is their properties and accuracy. Medical professionals must understand these distinctions to collect blood samples with relevant collection tubes, improving the diagnostic results.
Source: https://clinivex.wordpress.com/2023/06/09/edta-tubes-meaning-and-differencebetween-k2-k3-edta/