“…Redox‐active metalloproteins with low oxidation states are often oxygen sensitive; they will oxidize upon exposure to atmospheric oxygen and must be kept in an oxygen‐free environment. Some proteins, such as those with nonheme Fe(II) cofactors, are expressed with oxygen‐sensitive metals and need to be purified under an anaerobic or hypoxic atmosphere, which can be accomplished using a polyvinyl glove bag (Uchendu, Rafalowski, Cohn, Davoren, & Taylor, 2018). It is sometimes necessary to work with purified protein samples in an anaerobic environment.…”