Fetal bovine serum the harvesting of blood from the bovine fetus after the fetus is removed from the slaughtered cow. The blood is collected aseptically into a sterile container or blood bag and then allowed to clot. The normal method of collection is cardiac puncture, wherein a needle is inserted into the heart. This minimizes "the danger of serum contamination with micro-organisms from the fetus itself, and the environment". It is then centrifuged to remove the fibrin clot and the remaining blood cells from the clear yellow (straw) colored serum. The serum is frozen prior to further processing that is necessary to make
Blood, toil, tears, and sweat Blood, toil, tears, and sweat The phrase "blood, toil, tears and sweat" became famous in a speech given by Winston Churchill to the House of Commons of the Parliament of the United Kingdom on 13 May 1940. This was Churchill's first speech on 13 May 1940 to the House of Commons after having been offered the King's commission the previous Friday, to become Prime Minister of the United Kingdom in the first year of World War II. Churchill had replaced Neville Chamberlain on 10 May, and in this speech he asked the House to declare its confidence in his Government.