Clinical chemistry the denser blood cells and platelets to the bottom of the centrifuge tube, leaving the liquid serum fraction resting above the packed cells. This initial step before analysis has recently been included in instruments that operate on the "integrated system" principle. Plasma is in essence the same as serum, but is obtained by centrifuging the blood "without" clotting. Plasma is obtained by centrifugation "before" clotting occurs. The type of test required dictates what type of sample is used. A large medical laboratory will accept samples for up to about 700 different kinds of tests. Even the largest of laboratories rarely
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