Teichmann’s crystals

Hemhi (chlorohemin). According to the recommendations of lUPAC/IUB H. is an arbitrary chloroiron(III)-porphyrin complex (see also heme). Here H. is specifically the chloroiron(ni) complex of protoporphyrin (protohemin) C34H32ClFeN404, Mr 651.95 uv (pyridine) 557, 526, 418.5 nm. Long thin platelets or oblique prisms, first isolated from blood by Teichmann in 1852 and thus also known as Teichmann s crystals. H. is the usually isolated, stable form of heme. 

By treatment with glacial acetic acid, the protein component can be removed easily and the prosthetic group isolated, e.g. in the form of the easily crystallized chlorohemin (in hemin iron is trivalent, in heme it is bivalent). These (Teichmann s) crystals are excellent for identifying blood. 

E. Braun, Chapter 5 in Out of the Crystal Maze, ed. L. Hoddeson, E. Braun, J. Teichmann, S. Weart, Oxford University Press, New York, 1992. 

Hoddeson, L., Braun, E., Teichmann, J. and Weart, S. (editors) (1992) Out of the Crystal Maze (Oxford University Press, Oxford). 

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