Serum-separating tube Serum-separating tube 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," "tiger-tops," or "gold-topped tubes", referring to the stoppers which are either gold, red with a gold ring on top, or marbled red and grey. Marble-top tubes are also referred to as "tiger-tops" in some clinics. SPS tubes have a paler colour, sometimes leading confusion; these are known as "yellow tops" not "gold". Trademarked versions include Covidien "Corvac" tubes. They contain a special gel that separates blood cells from serum, as well as
Blood, toil, tears, and sweat The motion passed unanimously. This was the first of three speeches which he gave during the period of the Battle of France, which commenced on 10 May. Churchill had used similar phrases earlier, such as "Their sweat, their tears, their blood" in 1931, and "new structures of national life erected upon blood, sweat, and tears". Churchill's sentence, "I have nothing to offer but blood, toil, tears, and sweat," has been called a paraphrase of one uttered on 2 July 1849 by Giuseppe Garibaldi when rallying his revolutionary forces in Rome: "I offer hunger, thirst, forced marches, battle, and death." As