A large SST II vacutainer<unk> s, also known as<unk>  separator<unk> s or SSTs, are used in medical clinical chemistry tests requiring blood<unk> . SSTs are sometimes called "marble-top<unk> s", "tiger-tops", or "gold-topped<unk> s", referring to the stoppers which are either gold, red with a gold ring on top, or marbled red and grey. Marble-top<unk> s are also referred to as "tiger-tops" in some clinics. The stopper of SPS (sodium polyanethol sulfonate)<unk> s have a paler yellow colour, sometimes causing confusion; these are known as "yellow tops" not "gold". Trademarked versions of the SST include Covidien "Corvac"<unk> s. They contain a special gel that separates blood cells from<unk> , as well as particles to cause blood to clot quickly. The blood sample can then be centrifuged, allowing the clear<unk>  to be removed for testing. These<unk> s should be used with care when measuring drug or hormone levels because the drug or hormone may diffuse from the<unk>  into the gel, causing a reduction in measured level. The gel in SST II<unk> s (which appears slightly less opaque) is supposed to have less effect on drug levels in<unk> .
Serum-separating tube
Cytocentrifuge
Washed red blood cells
Hematology analyzer
Urine test strip
AutoAnalyzer
Helium dilution technique
M2-PK Test