Problems with protein quantification

[Amiodaron]

Hello!
For protein quantification I wanted to use the 2D-Quant Kit (GE), but had some problems with it. There is one thing I really cannot explain: How can I get several totally different protein concentrations by using just different dilutions of my protein solution?? Does anyone exist who also uses this kit? Or what`s your favoured method for protein quantification?

[danfive]

You can get different concentrations if you have a buffer reagent that interferes with the kit's reagents. A lot of salts and detergents can be diluted out so they don't interfere with the quantitation reaction, so they have their cutoff limits of what concentration or percent will work with the kit. Check your buffer recipes and kit manual for any interfering agents that may be in the protein solution.
I use microBCA kit from Pierce.