Cap Colors and Their Significance in Blood Collection Tubes

Color theory, in some or the other form, is applied everywhere, and the same goes for blood collection tubes. Even though these tubes might look vibrant and eye catchy, each bottle and its color cap signifies different things.

Professionals in the medical industry often use colors to identify the tubes, such as a red, blue, or lavender top blood collection tube. But there’s more to it, and to find out what’s unique about these tubes used in Phlebotomy, keep reading. 

Phlebotomy is a medical term that defines the process of withdrawing blood for lab tests. This involves using a medical needle to extract blood from veins.

The blood collection tube used for blood sampling is a sterile plastic vacutainer covered by a designated color rubber stopper. These tubes include additives that help preserve the required blood samples for longer and allow the examiner to identify the category of tests to perform according to the sample.

There are several collection tubes used for different purposes. Some of them are.

A red plastic tube signifies the presence of a clot stimulator and the absence of an anticoagulant, i.e., a blood thinner. A blood collector uses a red tube to collect serum for specific laboratory tests as indicated by the doctor. 

A red glass tube is a plain sterile vacutainer with no separators, anticoagulants, preservatives, or clot activators. Blood banks generally use these tubes for test purposes.

A gold tube consists of a serum separator gel and a clot activator. Several immunology, chemistry, and serology tests use this tube.

Ethylenediamine tetraacetic acid or edetic acid, commonly known as EDTA, is present in a pink test tube. Blood banks prefer these tubes to conduct necessary tests like red glass tubes.

A light green tube contains a gel separator and lithium heparin, which helps gather heparinized plasma. This tube helps in routine chemical tests.

A dark green tube containing sodium heparin collects whole blood or heparinized plasma that is useful for specific tests.

 

Consisting of an anticoagulant, i.e., potassium oxalate, and a preservative, i.e., sodium fluoride, a grey tube is either used in some particular chemistry medical tests or to conserve glucose in whole blood.

Similar to the pink tube, this also contains EDTA and is used for various tests like CBC, CEA, and blood donor screening.

Sodium citrate, a type of anticoagulant, is present in a light blue test tube and is helpful in coagulation, PT, and APTT tests.

For royal blue test tubes, there are two types one is equipped with EDTA, and the other is plain. Both of these are helpful in the process of collecting serum or whole blood to analyze trace elements.

ACD, medically known as anticoagulant citrate dextrose or acid citrate dextrose, is present in yellow tubes and is generally used for blood culture.

The quality of blood collection tubes can indirectly affect the accuracy of results. Therefore, laboratories should carefully import them from an authorized blood collection tubes supplier.

After all, everything matters when it comes to healthcare!