Vacutainer Guide
Vacutainer tubes are often used to collect blood samples in venipuncture procedures. But some of them are used to collect urine and to separate serum. Some of them contain additives designed for analytical testing. To make it easy for a phlebotomist to know which tube to use, a vacutainer has color-coded covers. Be sure to always remember the order of draw when pulling labs from patients.
Purple or lavender
This particular bottle is commonly used for Hematology tests, where whole blood is needed for analysis. It contains the anticoagulant EDTA (ethylenediaminetetraacetic acid) that binds calcium in the blood and metal ions. Other common tests using the purple shoe are full blood count (FBC), blood film, erythrocyte sedimentation rate (ESR), reticulocytes, Monospot test for EBV, red cell folate, parathyroid hormone (PTH), and HbA1C for diabetic control.
Pink
It is it specifically used for whole blood samples intended for transfusion labs. It is also used similar to the lavender tube, which means it contains the same additive. For tests of group and save (G&S), crossmatch (XM), and direct Coomb’s test (aka direct antiglobulin test), this tube is used.
Blue
This tube is often used for hematology tests involving the clotting system, such as coagulation screen, D-dimer, INR, activated partial thromboplastin ratio (APTR) and anti-Xa assay. Inactivated whole blood will be collected for analysis. This particular bottle contains buffered sodium citrate that reverses anticoagulation. Sodium citrate binds calcium ions in the blood, disrupting the clotting cascade. It is also used to stop blood from clotting while in the bag.
Yellow
Among all the vacutainers, the yellow one is the most versatile, used in a variety of tests that require separated serum analysis. These include biochemistry, urea and electrolyte (U+E), C-reactive protein (CRP), bone profile, magnesium assay, lipid profile, iron studies, vitamins, thyroid function test (TFT), troponins, amylase assay, drug levels, endocrinology, immunology, microbiology/virology, and toxicology.
It contains silica particles and a serum separating gel.
Gray
This bottle is used to analyze whole blood for glucose and lactate tests. It contains sodium fluoride that works as an antiglycolytic agent, and potassium oxalate as an anticoagulant. Some grey tubes use EDTA instead.
Red
This bottle is used mainly for biochemistry tests requiring serum, such as hormones, toxicology, bacterial and viral serology, antibodies, drug levels, and ionized calcium. Contain silica particles that serve as clot activators.
Dark green
Similar to the red bottle, a green vacutainer is seldom used, and only when doing biochemistry tests that require whole blood or heparinised plasma for analysis. It is often used for insulin, ammonia, and renin and aldosterone tests. It contains the anticoagulant sodium heparin.
Light green
This bottle is used for biochemistry tests that require separated heparinised plasma for analysis. It contains a plasma separator gel, and the anticoagulant lithium heparin.
The vacutainer bottles are standardized, but some laboratories have their own preferences. It is best to familiarize local guideline, before performing any phlebotomy activities.
