What each color of blood collection tube is used for?

Blood collection tubes, also known as vacutainers, come in various colors, each representing a specific additive or anticoagulant used for particular laboratory tests. The color-coding system is standardized to ensure that the collected blood samples are suitable for the intended tests. Here is a general guide to the most commonly used colors of blood collection tubes and their corresponding uses:

Red or Red-Gray (Tiger) Top: These tubes typically contain no additives and are used for collecting serum samples. After blood collection, the tube is allowed to clot, and then the sample is centrifuged to separate the serum from the clot. Serum is used for various chemistry tests, hormone assays, and some infectious disease testing.

Lavender or Purple Top: Lavender-top tubes contain the anticoagulant ethylenediaminetetraacetic acid (EDTA), which prevents blood from clotting by chelating calcium. They are used for complete blood count (CBC), blood cell differentials, and various hematological tests.

Light Blue Top: These tubes contain sodium citrate, an anticoagulant that binds to calcium, preventing blood clotting. They are used for coagulation studies, including prothrombin time (PT) and activated partial thromboplastin time (APTT).

Green or Light Green Top: Green-top tubes usually contain the anticoagulant heparin, which inhibits the activity of thrombin and other clotting factors. These tubes are used for various chemistry tests, such as ammonia levels and some blood gas analysis.

Gray Top: Gray-top tubes often contain potassium oxalate and sodium fluoride. The oxalate and fluoride act as anticoagulants and preserve glucose levels for glucose tolerance tests and lactate measurements.

Royal Blue Top: Royal blue-top tubes can come with or without an anticoagulant. They are used for trace element analysis and heavy metal testing. Some royal blue tubes contain EDTA or heparin as anticoagulants.

Yellow Top: Yellow-top tubes are used for blood cultures to detect bacterial or fungal infections in the blood.

Pink Top: Pink-top tubes contain the anticoagulant EDTA and are used for blood bank testing, including blood typing and cross-matching.

Light Yellow Top: These tubes typically contain acid citrate dextrose (ACD) as an anticoagulant and are used for blood bank procedures, such as donor blood collection and DNA testing.

It's important to note that while the color-coding system is widely used and standardized, variations may exist between different healthcare facilities or regions. Additionally, some tests may require specific types of tubes with additional additives, so it's essential to follow the laboratory's guidelines and protocols for proper blood sample collection.