Tianyu, My suggestion is to determine the molar absorption coefficient empirically using the Edelhoch method ( http://www.rpgroup.caltech.edu/courses/PBL/bootcamp_June07/pdf/articles/Edelhoch1967.pdf). This involves measuring the absorbance at 280nm of your native and your unfolded protein (a nice protocol and explanation here: http://mail.ypu.edu.tw/~wnhuang/apparatus/ps0301.pdf), and then measuring your protein concentration using this absorption coefficient in Beer-Lambert's law.
Emily. On Tue, Mar 10, 2015 at 5:49 PM, Gmail <[email protected]> wrote: > Dear all, > > > > I have a (heavily and heterogeneously) glycosylated protein that has > very low OD280 absorption. I wondered whether the glycans will have any > effect on the accuracy of BCA or Bradford assay. Amino acid analysis > doesn’t seem to be any better because carbohydrates will interfere with > sample analysis and quantification. Any suggestion about other methods that > we could try to measure the concentration of this protein? Much appreciated! > > > > Best, > > Tianyu > > >
