Design of experiments

[#1]

Hi everyone, 

first of all, excuse my english because I am not a native english speaker. I am a beginner in the field of design of experimens and this is why I am looking for insights. My problem is the folowing: 

1. I need to optimize the concentration of 7 proteins contained in the cell culture medium we use

2. We know that all these 7 proteins have an significant effect on the response ( yield)

3. We don't know if there is any interaction between the proteins 

4. We know that the effect of some proteins is not linear to the concentration: this means that higher concentration than usual can have a negative impact on the yield ( possible quadratic effect ) 

5.  We also know that the cells used as starting material for cell culture have a big impact  on the yield, but since we can't control that factor, we are thinking about using it as a blocking factor. 

My questions are the following : 

- How do we start ? do we evaluate the blocking factor in the first plan  we make ? 

- Do we need to use three level per factor ( concentration of protein) or two to reduce the number of assay ( but we could miss quadratic effect) 

Thank you in advance. 

[#2]

I agree with Pete...all we can do is try to get the OP to recognize their limitations regarding the process of designing experiments so they might seek the advice they need.

While I respect the intent of the Easy DOE platform, it seems to me an oxymoron.

[#3]

Hello, thank you for your answer. We do plan to be supervised by a consultant. I just want to have another point of view.