Before i can isolate an unknown protein, i would have to decide how i
would know when i have it. Will you please help me to solve this.
Since i don't understand so clearly, will you please use some easy to
understand reasoning so that i can grasp it.
                                 Ted.

What information do you have concerning the protein?
If you have structural information, it may be possible to raise a
specific antibody against a recombinant peptide.
If you have functional information, it may be possible to assay
fractions from whatever isolation procedure you use.

Ted McCall, 

To tell you the truth, since you've asked why this question has not
been answered yet (http://answers.google.com/answers/threadview?id=437834),
I wouldn't answer this question because it seems to me like a class
assignment. Of course, I could be wrong, and I apologise if I
misunderstood your question. Maybe you could explain a little more
what you're looking for, which protein we're talking about, and what
kind of answer you're expecting.

Ted Mcall,

We are all rooting for you. You will get it. Keep at it!