Serum-separating tube
Encyclopedia
Serum-separating tubes, also known as serum separator tubes or SSTs, are used in medical clinical chemistry tests requiring blood
serum
.
SSTs are sometimes called "marble-top tubes" or "yellow topped tubes", referring to the stoppers which are either gold or red-gray. Trademarked versions include Covidien
"Corvac" tubes.
They contain a special gel that separates blood cells from serum, as well as particles to cause blood to clot quickly. The blood sample may then be centrifuged, allowing the clear serum to be removed for testing.
These tubes should be used with care when measuring therapeutic endocrine
levels because the drug/hormone may diffuse from the serum into the gel, causing a reduction in measured drug level.
The gel in SST II tubes (which appears slightly less opaque) is supposed to have less effect on drug levels in serum.
Blood
Blood is a specialized bodily fluid in animals that delivers necessary substances such as nutrients and oxygen to the cells and transports metabolic waste products away from those same cells....
serum
Blood plasma
Blood plasma is the straw-colored liquid component of blood in which the blood cells in whole blood are normally suspended. It makes up about 55% of the total blood volume. It is the intravascular fluid part of extracellular fluid...
.
Covidien
Covidien , formerly Tyco Healthcare, is a healthcare device and supply company, incorporated in Dublin, Ireland, although its corporate offices are located in Mansfield, Massachusetts. On June 29, 2007, Covidien became an independent publicly traded company after being spun off from Tyco...
"Corvac" tubes.
They contain a special gel that separates blood cells from serum, as well as particles to cause blood to clot quickly. The blood sample may then be centrifuged, allowing the clear serum to be removed for testing.
These tubes should be used with care when measuring therapeutic endocrine
Drug
A drug, broadly speaking, is any substance that, when absorbed into the body of a living organism, alters normal bodily function. There is no single, precise definition, as there are different meanings in drug control law, government regulations, medicine, and colloquial usage.In pharmacology, a...
levels because the drug/hormone may diffuse from the serum into the gel, causing a reduction in measured drug level.
The gel in SST II tubes (which appears slightly less opaque) is supposed to have less effect on drug levels in serum.
Further reading
SST Tubes are NOT known as Yellow Tops. Gold Top is acceptable, however SST is the only correct terminology. Yellow Tops are VERY different and the use of the term "Yellow Top" with an inexperienced Phlebotomist or Nurse could result in the sample being rejected by the lab for incorrect tube/sample as there are yellow top tubes which contain different additives from the SST. In addition, taking the order of draw into consideration, a yellow top tube used in confusion of terminology where an SST was required, when more than one kind of tube is being drawn, can and will result in sample cross contamination, making most, if not all tubes rejectable in the lab.- VacutainerVacutainerVacutainer is a brand of test tubes specifically designed for venipuncture, which was developed in 1947 by Joseph Kleiner.In phlebotomy the word “vacutainer” has come to be used as a genericized trademark to describe any vacuum-based blood collection vial, regardless of brand. Becton Dickinson...
- VenipunctureVenipunctureIn medicine, venepuncture, venopuncture or venipuncture is the process of obtaining intravenous access for the purpose of intravenous therapy or for blood sampling of venous blood. This procedure is performed by medical laboratory scientists, medical practitioners, some EMTs, paramedics,...