In article <[email protected]>, [email protected] says... > > Hello Everyone > > I was trying to prepare 5x sds sample buffer and it has become brown color > instead of blue color. Could anyone please tell me what is the reason and > please tell me your suggestions. > > The 5x sample buffer recipe > > 250mM tris-hcl ph 6.8(1M stock)------10ml > 10% sds-------------------------4gr > 50% glycerol(87%stock)------------------23ml > 0.02% Bromphenol blue-----0.008gr > final volume-------------------------40ml with DDh20 including 1.4ml of 0.5 > M B-mercaptoethanol but I didnt add here.
Promophenolblue is an indicator with a colour chnage from blue to yellow. My guess is that your solution has a pH just around the pKa value of bromophenolblue (3.6). Remember that the pH of most buffers change upon dilution, because it is the activity, rather than the concentation that determines pH. In addition, the high glycerol content may also affect the colour. Is SDS actually soluble under these conditions? -- Car (noun): erratically moving obstacle on the road _______________________________________________ Methods mailing list [email protected] http://www.bio.net/biomail/listinfo/methods
