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,...

BACKGROUND Rasburicase (Fasturtec® or Elitek®, Sanofi-Aventis), the recombinant form of urate oxidase from Aspergillus flavus, is a therapeutic enzyme used to prevent or decrease the high levels of uric acid in blood that can occur as a result of chemotherapy. It is produced by Sanofi-Aventis and currently purified via several standard steps of chromatography. This work explores the feasibility...

Absolute stereochemistry of oils and viscous liquids can be difficult to determine. Co-crystallization involves generating a crystalline material consisting of more than one neutral compound. The combination of co-crystallization with both X-ray diffraction and chiral HPLC was particularly powerful in overcoming these difficulties for a series of chiral 3-arylbutanoic acids. Co-crystallization ...

Crown ether complexation solubilizes organic and inorganic salts in nonpolar media. Induction of crystallization from such solutions can result in crystallization of the free salt rather than the complex. This affords the opportunity to examine solvent effects on the crystallization of salts and other polar materials, leading to the modification of crystal shape and lattice. This approach, whic...

All of the macromolecules are polymers consist of amino acids, ribonucleotides and deoxyribonucleotides, sugars of various sorts, fatty acids, etc. Crystallization of macromolecules is complex process based on finding individual conditions and parameters leading to formation of crystal. Experience and reproducibility are guides in making crystallization experiments. All of the macromolecules ar...

Solutions of maltodextrins (MD) with the dextrose equivalent (D.E.) 9-12 and D.E. 23-27 were mixed with lactose solutions at different ratios. Freeze-dried amorphous solids of lactose and lactose-MD were prepared from solutions containing 20% total solids. The ratios of lactose and MD were 90:10, 80:20, and 70:30 (w/w). Crystallization rate of amorphous lactose was followed from changes in wate...

Of a range of glycosaminoglycans, heparin and heparan sulphate were the most effective inhibitors in vitro of CaCO3 (calcite) crystallization as assayed by conductimetric measurements. The possible role of such glycosaminoglycans in modulating calcium-salt crystallizations in vivo is discussed.

9,10-dihydro-9,10-ethano-anthracene-11,12-dicarboxylic acid disodium salt (dheas) was synthesized andused as a nucleating agent for poly(1-butene) (ipb). the isothermal crystallization kinetics of ipb havingdifferent nucleating agents were investigated by differential scanning calorimetry (dsc) and polarized opticalmicroscopy (pom). the results showed that the nucleating agents increased the cr...

X-ray crystallography requires high quality crystals above a given size. This requirement not only limits the proteins to be analyzed, but also reduces the speed of the structure determination. Indeed, the tertiary structures of many physiologically important proteins remain elusive because of the so-called "crystallization bottleneck". Once microcrystals have been obtained, crystallization con...