Fetal bovine serum and virus, endotoxin, haemoglobin, IgG and total protein assays. Ethical questions have been raised regarding the blood collection process due to the potential suffering caused to the fetus. Although anoxia or active slaughter could be used to induce unconsciousness or death prior to serum harvesting, exposure of live unborn calves to oxygen can cause them to gain awareness before being killed, resulting in active debate about the ethics of harvesting serum. Fetal bovine serum is commercially available from many manufacturers, and because cells grown in vitro are highly sensitive, customers usually test specific batches to check for suitability for their
Mucus mucus has a threefold higher potential to limit agent penetration than purified mucus. Mucus Mucus ( ) is a polymer. It is a slippery aqueous secretion produced by, and covering, mucous membranes. It is typically produced from cells found in mucous glands, although it may also originate from mixed glands, which contain both serous and mucous cells. It is a viscous colloid containing inorganic salts, antiseptic enzymes (such as lysozymes), immunoglobulins, and glycoproteins such as lactoferrin and mucins, which are produced by goblet cells in the mucous membranes and submucosal glands. Mucus serves to protect epithelial cells (that line the