A couple questions about the bradford method

[vande060]

Homework Statement

In the protocol for the bradford method I am told to prepare two blanks of water of .15M NaCl. I don't understand why I need two of them. Don't I just need one of them for placing into the photometer after I have set 0% transmission to set 100% transmission by.

should I put some of the coomassie brilliant blue, in one of these, both of them, or none of them?

I really don't get why I need two of them, any help would be appreciated

Homework Equations

The Attempt at a Solution

 

[vande060]

Is it that one of the blanks is left with water to zero the machine and the other blank has just coomassie brilliant blue added to it, measured for absorption, and then subtract the absorption from the standards when plotting the standard curve, because that is what I am told to do for my Bicinchoninic acid assay.

Also, why do I have serial dilutions of the unknown, is it just in case the stock solution of unknown falls outside of the range of what concentrations are detectable by my test.

Furthermore, if I am running a Bicinchoninic acid assay do I have to do serial dilutions just as I did for the bradford method.