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【求助】用还原能力评价抗氧化活性问题
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还原能力过程如下： Various concentrations of chestnut extracts (2.5 ml) were mixed with 2.5 ml of 200 mM sodium phosphate buf- fer (pH 6.6) and 2.5 ml of 1% potassium ferricyanide. The mixture was incubated at 50 C for 20 min. After 2.5 ml of 10% trichloroacetic acid (w/v) was added, the mixture was centrifuged at 1000 rpm for 8 min (Centorion K24OR-2003 refrigerated centrifuge). The upper layer (5 ml) was mixed with 5 ml of deionised water and 1 ml of 0.1% of ferric chloride, and the absorbance was measured spectrophoto- metrically at 700 nm (Barros et al., 2007). The extract con- centration providing 0.5 of absorbance (EC50) was calculated from the graph of absorbance at 700 nm against extract concentration. BHA and a-tocopherol were used as standards. 请问你们离心后会分层吗？我做的不会分层，还是本来就不会分层，但是文献上又说是上清液？ |
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siwei2020
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guodong1997
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shiweidong7727
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