Blood Collection Tubes and Additives

What you need to know about the phlebotomy test tubes
Yellow-Topped Tubes
the additive sodium polyanethol sulfonate (SPS) is for blood culture specimin collections in microbiology. Should be gently inverted in the vacuum tube 8 times for comlete mixing of SPS with the blood. It should be noted that tubes containing ACD (acid citrate dextrose) also use the yellow color code. These tubes are mainly used to preserve blood for donation. Also, ACD is used for specialty blood banking, such as human leukocyte antigen (HLA) typing and DNA testing. The yellow-topped tubes need to be gently inverted 8 times immediately after blood collection for additive/blood mixing.
Light Blue-Topped Tubes
Many coagulation procedures, such as prothrombin time (PT) and activated partial thromboplastin time (PTT), are done on blood collected in light blue tubes which contain sodum citrate. Tubes must be filled, or coagulation results will be inaccurate, which could lead to the wrong treatment for the patient. Sodim citrate buffers coagulation factors, making it the best anticoagulant for coagulation testing. The light blue tubes should be inverted three or four times as soon as the blood is collected.
Red-Topped Tubes
The red tubes indicate a tube without an anticoagulant or plymer (gel) barrier and is used for the collection of serum. Thus, the collected blood will clot in this tube. After the blood is collected in the tube, the clotting process begins and takes at least 30 minutes for the fibrin clot to form. However, BD VACUTAINER has developped the new red rapid serum tube (RST) that has a 5 minute clotting time.
Green-Topped Tubes
The anticoagulants sodium heparin and lithium heparin are found in green tubes. These tubes are used in various laboratory assays requiring plasma or whole blood. which are mainly chemical tests. Lithium heparin tubes are used for many assays, including: GLUCOSE, BLOOD UREA NITRPGEM (BUN), IONIZED CALCIUM, CREATININE, OR ELECTROLYTE STUDIES. However, this anticoagulant is not suitable for tests involving the measurement of lithium or folate levels. Similarly, sodium heparin tubes should not be used for assays that measure the sodium concentration. Green tubes should not be used for collections for blood smears. When used for cytogenetic studies, these tubes must be sterile. Should be inverted 8 gently inersions immediately after blood collection.
Tiger-Topped Tubes
These tubes should be gently inverted after obtaining the blood to ensure mixing of the clot activator. These tubes contain a polymer barrier in the bottom of the tube. the tube needs to be gently inverted 5 to 8 times and set for 30 minutes prior to centrifugation.
Lavendar-Topped Tubes
Are used for most hematology procedures, such as the complete blood count (CBC), (RBCs), (WBCs), platelet count, hematocrit, differentials, hemoglobin, mean corpuscular hemoglobin, means corpuscular hemoglobin concentration, and mean cell volume, among others. Also this tube is used for molecular diagnostic testing, immunology, and hemoglobin A1c. the tube needs to be inverted 8 to 10 times after blood collection.