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, Sweat & Tears 4 Blood, Sweat & Tears 4 Blood, Sweat & Tears 4 is the fourth album by the band Blood, Sweat & Tears, released in 1971. It peaked at number 10 on the Billboard Pop albums chart. The band invited former member Al Kooper to contribute the song "John the Baptist (Holy John)." Trombonist Dave Bargeron replaced Jerry Hyman. David Clayton-Thomas left as lead vocalist to pursue a solo career after the release of "BS&T 4", as did founding members Dick Halligan and Fred Lipsius. Clayton-Thomas would return to the lineup for "New City". Writing for Allmusic, critic William Ruhlman wrote "the