Sigma Aldrich Company

The calf thymus dsDNA and ssDNA (as lyophilized powder) were obtained from Sigma-Aldrich Company (Germany). dsDNA/ssDNA stock solutions (lOOmg/L) were prepared with TE solution (10 mM Tris-HCl, 1 mM EDTA, pH 8.00) and kept frozen. More dilute solutions of DNA were prepared with 0.05 M acetate buffer solution containing 20 mM NaCl (ABS pH 4.80) ultrapure distilled water. Other chemicals were of analytical reagent grade. 

A suitable grade of retinyl palmitate may be obtained from Sigma-Aldrich Company. 

Sigma-Aldrich Company Ltd Tennants (Distribution) Ltd Thew, Arnott and Co Ltd... 

Lissamine fast yellow (LFY) dye was purchased from Sigma-Aldrich Company (India) and was used as received. All chemicals used were of AR grade. The photocatalyst ZnO used in the study obtained from Merck was about 99% pure. All solutions were prepared in double-distilled water. The chemical stmcture of LFY is given in Fig. 2. 

Aldrich Technical Bulletin, AL134, Sigma Aldrich Company 1997. 

Most reagents are available from the Sigma - Aldrich company... 

Aldrich Handbook of Fine Chemicals. 2006. Sigma-Aldrich Company, SL Louis, Mo. 

An extensive list of the commercially available resins is available from Sigma-Aldrich (www.sigmaaldrich.com), Novabiochem (www.novabiochem.com), Fluka and other chemical companies. Sigma-Aldrich and Novabiochem have excellent catalogs. In addition, the Novabiochem catalog and website are a rich source of useful technical information. 

Sigma-Aldrich Laborchemikalien (Germany) Sinopec Qilu Company (China)... 

Web site www.sigma-aldrich.com Parent Company Sigma-Aldrich Co. (US)... 

Reagents. Perylene was obtained from Sigma Chemical Company (St. Louis, Missouri). All other PAHs were supplied by Aldrich Chemical Company (Milwaukee, Wisconsin) and were reported to contain less that 3% impurities. All PAHs were used without further purification. Isopropyl ether (99%) for extraction work was also purchased from Aldrich. Hydroquinone, a fluorescent stabilizer present in the ether, was removed prior to solution preparation by rotary evaporation. Fluorometric-grade 1-butanol was supplied by Fisher Scientific Company (Fair Lawn, New Jersey). All solutions for extractions of PAHs were prepared by evaporating portions of a stock cyclohexane solution and diluting to the appropriate volume with isopropyl ether. Fluorescence measurements were performed on 1 10 dilutions of the stock and final organic phase solutions. The effect of dissolved CDx on the fluorescence intensity of the organic phase PAH was minimized by dilution with isopropyl ether. 

To address new researchers entering the field of PLED, especially those, not trained in organic synthesis, we should mention that many LEP are now available commercially from several companies, such as Aldrich (www.sigma-aldrich.com), American Dyes Source (www.adsdyes.com), H.W. Sands (http //www.hwsands.com/), and Dow Chemicals (http //www.dow.com/pled /). 

Sigma Aldrich, USA. The company had sales of 1.7 billion in 2005 and serves 60,000 accounts representing over one million individual customers. Apart from offering 100,000 small and big molecules, including cell culture media, it has also 30,000 items of laboratory equipment available. Under the name SAFC Pharma, a 65 million PFC (including HPAI) custom manufacturing business is operated. 

Reagents. Sigma Chemical Company supplied quinaldic acid, trimesic acid, glycine, caffeine, 5-chlorouracil, ethidium bromide (EB), and fluores-camine. Analabs supplied stearic acid, 2,4 -dichlorobiphenyl, and 2,2, 5,5 -tetrachlorobiphenyl. Eastman supplied phenanthrene. Aldrich supplied pyrene,... 

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