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 & Tea Blood, Sweat & Tea Blood, Sweat & Tea is a book by ambulance technician Brian Kellett, writing under the pseudonym Tom Reynolds, about life in the London Ambulance Service. The book is compiled from posts and correspondence from the blog Random Acts of Reality, one of the earliest high-readership blogs in England. The book covers Reynolds's career from 2003–2006, and discusses his career as an emergency medical technician and a rapid responder. Although often extremely critical of NHS policies and management, the book was extremely well received within the European emergency services, and the book (with its associated blog) is