Cary uv vis multicell peltier spectrophotometer

MDA content was used as an indicator of lipid peroxidation. The adducts generated by the reaction of MDA with thiobarbituric acid allows the indirect measurement of MDA content. Colon tissues were homogenized and centrifuged as described above. The same volume of supernatant and trichloroacetic acid solution at 20% (containing 0.8% butylated hydroxytoluene to prevent nonspecific chromophore formation during the assay procedure) was mixed to precipitate proteins. After centrifugation at 1000g for 10 minutes, the resulting supernatant was mixed with Tris-TBA (26 mmol/L Tris and 120 mmol/L thiobarbituric acid) and 0.6 mol/L HCl in a volume ratio of 5:4:1 and heated in a water bath at 80°C for 15 minutes. The absorbance of the supernatants was measured with a Cary UV-Vis Multicell Peltier spectrophotometer (Agilent Technologies, Les Ulis, France) at 532 nm. A standard curve was established by preparing standard solutions containing various concentrations of MDA (0.25, 0.5, 1, and 2 mmol/L) from a 10 mmol/L stock solution (Elabscience Biotechnology, Houston, TX). The standard solutions were processed as the samples. Concentration of MDA was established against the standard curve, and MDA content was expressed as nmol.mg^-1 protein and normalized as compared with the control.