title: Trial by fire: are the crystals macromolecules?
abstract: Protein crystallization screens frequently yield salt crystals as well as protein crystals. A simple method for determining whether a crystal is composed of salt or macromolecules is suggested. A drop containing one or more crystals is transferred to a glass cover slip and the cover slip is then passed through the flame of a Bunsen burner. Macromolecule crystals are destroyed by this treatment, while salt crystals generally remain. The test can be performed after other commonly used tests such as crushing and staining.
authors.affiliation: Michigan State University, Department of Microbiology and Molecular Genetics, USA.
authors.forename: Kannan
authors.initials: K
authors.lastname: Raghunathan
authors.forename: Paul T
authors.initials: PT
authors.lastname: Harris
authors.forename: Dennis N
authors.initials: DN
authors.lastname: Arvidson
mesh_terms: D003460:Crystallization; D011506:Proteins / Q000032:analysis*; D012492:Salts / Q000032:analysis
chemical_list: D011506:Proteins; D012492:Salts
references.citation: Acta Crystallogr D Biol Crystallogr. 2005 Jan;61(Pt 1):60-6
references.pmid: 15608376
references.citation: Proc Natl Acad Sci U S A. 1964 Sep;52:833-9
references.pmid: 14212562
references.citation: Acta Crystallogr D Biol Crystallogr. 2006 Mar;62(Pt 3):339-46
references.pmid: 16510981
references.citation: Acta Crystallogr Sect F Struct Biol Cryst Commun. 2009 Jul 1;65(Pt 7):702-4
references.pmid: 19574644
references.citation: Methods Mol Biol. 2007;363:131-51
references.pmid: 17272840
references.citation: Nat Struct Mol Biol. 2006 Jan;13(1):44-8
references.pmid: 16341226
references.citation: Acta Crystallogr Sect F Struct Biol Cryst Commun. 2010 Apr 1;66(Pt 4):478-84
references.pmid: 20383027
references.citation: Nature. 1998 Jan 8;391(6663):203-6
references.pmid: 9428770
references.citation: Acta Crystallogr D Biol Crystallogr. 2007 Apr;63(Pt 4):526-35
references.pmid: 17372358
references.citation: Acta Crystallogr D Biol Crystallogr. 2003 Jan;59(Pt 1):139-41
references.pmid: 12499550
references.citation: Acta Crystallogr D Biol Crystallogr. 2002 Nov;58(Pt 11):1901-6
references.pmid: 12393920
references.citation: Acta Crystallogr Sect F Struct Biol Cryst Commun. 2009 Jun 1;65(Pt 6):629-31
references.pmid: 19478449
references.citation: Anal Chem. 2009 May 15;81(10):3769-75
references.pmid: 19388631
references.citation: Acta Crystallogr Sect F Struct Biol Cryst Commun. 2010 Mar 1;66(Pt 3):364-72
references.pmid: 20208182
references.citation: Acta Crystallogr D Biol Crystallogr. 2004 Apr;60(Pt 4):696-702
references.pmid: 15039558