Category: alcohols-buliding-blocksIn 2013 ,《Characterization of salt interferences in second-harmonic generation detection of protein crystals》 appeared in Journal of Applied Crystallography. The author of the article were Closser, R. G.; Gualtieri, E. J.; Newman, J. A.; Simpson, G. J.. The article conveys some information:
Studies were undertaken to assess the merits and limitations of second-harmonic generation (SHG) for the selective detection of protein and polypeptide crystal formation, focusing on the potential for false positives from SHG-active salts present in crystallization media. The SHG activities of salts commonly used in protein crystallization were measured and quant. compared with reference samples. Out of 19 salts investigated, six produced significant background SHG and 15 of the 96 wells of a sparse-matrix screen produced SHG upon solvent evaporation SHG-active salts include phosphates, hydrated sulfates, formates and tartrates, while chlorides, acetates and anhydrous sulfates resulted in no detectable SHG activity. The identified SHG-active salts produced a range of signal intensities spanning nearly three orders of magnitude. However, even the weakest SHG-active salt produced signals that were several orders of magnitude greater than those produced by typical protein crystals. In general, SHG-active salts were identifiable through characteristically strong SHG and negligible two-photon-excited UV fluorescence (TPE-UVF). Exceptions included trials containing either potassium dihydrogen phosphate or ammonium formate, which produced particularly strong SHG, but with residual weak TPE-UVF signals that could potentially complicate discrimination in crystallization experiments using these precipitants. In the experiment, the researchers used many compounds, for example, Potassium sodium (2R,3R)-2,3-dihydroxysuccinate tetrahydrate(cas: 6381-59-5Category: alcohols-buliding-blocks)
Potassium sodium (2R,3R)-2,3-dihydroxysuccinate tetrahydrate(cas: 6381-59-5) is a ferroelectric crystal with a high piezoelectric effect and electromechanical coupling coefficient. Category: alcohols-buliding-blocks It is utilized to break up emulsion in organic synthesis as well as a common precipitant in protein crystallography.
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